The Local Coordination Committees of Syria said 10 people were killed in the country, two of them in Douma, CNN reported. The Syrian Observatory for Human Rights said 20 people were injured in Douma as the monitors arrived in the city.
Under the Arab League plan, security forces are supposed to withdraw from the cities that have become centers of opposition protest. The monitors arrived two days ago and were scheduled to visit Daraa, Hama and Idlib Thursday. Daraa is where the anti-regime uprising erupted March 17..
In Daraa, an activist told The New York Times he had seen little sign of the government complying with the Arab League plan. Anwar Farres said he and other activists were waiting outside a hotel for the monitors but had seen no sign of them.
"This place is like a military base," Farres said. "Our people will meet them with or without the presence of government forces."
At least two people were killed Wednesday in Homs, activists said.
Activist video monitored by United Press International showed league observers wearing reflective orange vests visiting Homs' flashpoint Bab Amr neighborhood. The video showed shattered houses and sounds of heavy gunfire in the background.
One observer in the video, appearing calm, could be seen turning toward the gunfire and taking a photo. Someone screamed "explosions" in Arabic.
Another activist video showed Bab Amr residents taking observers to see the body of a boy they said was 5 years old and had been killed by security forces. The video showed them removing blankets from the child's body to reveal a projectile wound about the size of a golf ball below his left armpit.
The observer team was initially denied entry into the besieged neighborhood because a Syrian army lieutenant colonel was escorting them. The officer eventually stepped aside.
Activists later claimed the observers had been unable to visit a secret Assad-regime detention facility because of Syrian army gunfire, The Daily Telegraph reported.
The death tolls and other accounts could not be independently confirmed due to restrictions imposed on journalists by the Syrian government.
Amnesty International and other rights and activist groups say at least 15,000 and perhaps more than 30,000 Syrians remain in detention.
The regime of President Bashar Assad insists it is fighting a terrorist insurgency that has killed 2,000 soldiers and police. The United Nations estimates more than 5,000 people have been killed since the popular uprising and harsh regime crackdown began.