Syrian tank is seen in a neighborhood of Zabadani, near Damascus, in Syria February 15, 2012. Syria's President Bashar al-Assad has called for referendum on a new constitution that would effectively end nearly five decades of single party rule, it was announced today. UPI | License Photo
Syrian soldiers who defected to join the "Free Syrian Army" are seen in Al Baiadah near Homs in Syria, February 15, 2012. Syria's President Bashar al-Assad has called for referendum on a new constitution that would effectively end nearly five decades of single party rule, it was announced today. UPI | License Photo
Demonstrators protest against Syria's President Bashar al-Assad in al-Midan district in Damascus February 15, 2012. Syria's President Bashar al-Assad has called for referendum on a new constitution that would effectively end nearly five decades of single party rule, it was announced today. UPI | License Photo
Demonstrators protest against Syria's President Bashar al-Assad in al-Midan district in Damascus February 15, 2012. Syria's President Bashar al-Assad has called for referendum on a new constitution that would effectively end nearly five decades of single party rule, it was announced today. UPI | License Photo
Smoke is seen rising from Bab Amro near Homs as government forces continue to bomb the rebel areas in Syria on February 15, 2012. Syria's President Bashar al-Assad has called for referendum on a new constitution that would effectively end nearly five decades of single party rule, it was announced today. UPI | License Photo
Syrian residents stay in a shelter in the district of Bab Amro in Homs as government forces continue to bomb the rebel areas in Syria on February 15, 2012. Syria's President Bashar al-Assad has called for referendum on a new constitution that would effectively end nearly five decades of single party rule, it was announced today. UPI | License Photo
A Syrian tank is seen in Bab Amro near the city of Homs, Syria on February 14, 2012. Syrian government forces renewed their assault on the rebellious city of Homs Tuesday in what activists described as the heaviest shelling in days, as the U.N. human rights chief raised fears of civil war. UPI | License Photo
Shows smoke rising from a building reportedly following shelling by the Syrian army in the Bab Amr neighborhood of Homs, Syria on February 14, 2012. Syrian government forces renewed their assault on the rebellious city of Homs Tuesday in what activists described as the heaviest shelling in days, as the U.N. human rights chief raised fears of civil war. UPI | License Photo
Syrian tank is seen in a neighborhood of Zabadani, near Damascus, in Syria February 15, 2012. Syria's President Bashar al-Assad has called for referendum on a new constitution that would effectively end nearly five decades of single party rule, it was announced today. UPI | License Photo
Demonstrators protest against Syria's President Bashar al-Assad in al-Midan district in Damascus February 15, 2012. Syria's President Bashar al-Assad has called for referendum on a new constitution that would effectively end nearly five decades of single party rule, it was announced today. UPI | License Photo
Demonstrators protest against Syria's President Bashar al-Assad in al-Midan district in Damascus February 15, 2012. Syria's President Bashar al-Assad has called for referendum on a new constitution that would effectively end nearly five decades of single party rule, it was announced today. UPI | License Photo
A Syrian girl with the flag of independence colored on her face attends a protest against Syria's President Bashar al-Assad, in Al-drbaseh, Northern Syria, February 14, 2012. Syrian government forces renewed their assault on the rebellious city of Homs on Tuesday in what activists described as the heaviest shelling in days, as the U.N. human rights chief raised fears of civil war. UPI | License Photo
Demonstrators burn a poster of Syria's President Bashar al-Assad during a protest in Al Mazaa in Damascus, Syria on February 12, 2012. Syrian government forces renewed their assault on the rebellious city of Homs Tuesday in what activists described as the heaviest shelling in days, as the U.N. human rights chief raised fears of civil war. UPI | License Photo
Damaged houses are seen in Bab Amro in the city of Homs, Syria on February 14, 2012. Syrian government forces renewed their assault on the rebellious city of Homs Tuesday in what activists described as the heaviest shelling in days, as the U.N. human rights chief raised fears of civil war. UPI | License Photo
Demonstrators gather during a protest against Syria's President Bashar al-Assad, in Al-drbaseh, Northern Syria, February 14, 2012. Syrian government forces renewed their assault on the rebellious city of Homs on Tuesday in what activists described as the heaviest shelling in days, as the U.N. human rights chief raised fears of civil war. UPI | License Photo
Demonstrators gather during a protest against Syria's President Bashar al-Assad, in Al-drbaseh, Northern Syria, February 14, 2012. Syrian government forces renewed their assault on the rebellious city of Homs on Tuesday in what activists described as the heaviest shelling in days, as the U.N. human rights chief raised fears of civil war. UPI | License Photo
Demonstrators gather during a protest against Syria's President Bashar al-Assad, in Al-drbaseh, Northern Syria, February 14, 2012. Syrian government forces renewed their assault on the rebellious city of Homs on Tuesday in what activists described as the heaviest shelling in days, as the U.N. human rights chief raised fears of civil war. UPI | License Photo
Demonstrators gather during a protest against Syria's President Bashar al-Assad, in Al-drbaseh, Northern Syria, February 14, 2012. Syrian government forces renewed their assault on the rebellious city of Homs on Tuesday in what activists described as the heaviest shelling in days, as the U.N. human rights chief raised fears of civil war. UPI | License Photo
Demonstrators gather during a protest against Syria's President Bashar al-Assad, in Al-drbaseh, Northern Syria, February 14, 2012. Syrian government forces renewed their assault on the rebellious city of Homs on Tuesday in what activists described as the heaviest shelling in days, as the U.N. human rights chief raised fears of civil war. UPI | License Photo
Demonstrators gather during a protest against Syria's President Bashar al-Assad, in Al-drbaseh, Northern Syria, February 14, 2012. Syrian government forces renewed their assault on the rebellious city of Homs on Tuesday in what activists described as the heaviest shelling in days, as the U.N. human rights chief raised fears of civil war. UPI | License Photo
Demonstrators gather during a protest against Syria's President Bashar al-Assad, in Al-drbaseh, Northern Syria, February 14, 2012. Syrian government forces renewed their assault on the rebellious city of Homs on Tuesday in what activists described as the heaviest shelling in days, as the U.N. human rights chief raised fears of civil war. UPI | License Photo
Demonstrators gather during a protest against Syria's President Bashar al-Assad, in Al-drbaseh,Northern Syria, February 14, 2012. Syrian government forces renewed their assault on the rebellious city of Homs on Tuesday in what activists described as the heaviest shelling in days, as the U.N. human rights chief raised fears of civil war. UPI | License Photo
Demonstrators burn Russian and Chinese flags during a protest against Syria's President Bashar al-Assad in Al Mazaa in Damascus, Syria on February 12, 2012. Syrian government forces renewed their assault on the rebellious city of Homs Tuesday in what activists described as the heaviest shelling in days, as the U.N. human rights chief raised fears of civil war. UPI | License Photo
Damaged houses are seen in Bab Amro in the city of Homs, Syria on February 14, 2012. Syrian government forces renewed their assault on the rebellious city of Homs Tuesday in what activists described as the heaviest shelling in days, as the U.N. human rights chief raised fears of civil war. UPI | License Photo
Damaged houses are seen in Bab Amro in the city of Homs, Syria on February 14, 2012. Syrian government forces renewed their assault on the rebellious city of Homs Tuesday in what activists described as the heaviest shelling in days, as the U.N. human rights chief raised fears of civil war. UPI | License Photo
A damaged car is seen in Bab Amro in the city of Homs, Syria on February 14, 2012. Syrian government forces renewed their assault on the rebellious city of Homs Tuesday in what activists described as the heaviest shelling in days, as the U.N. human rights chief raised fears of civil war. UPI | License Photo