ALEPPO, Syria, Oct. 28 (UPI) -- Syrian rebels on Friday announced the launch of an offensive in Aleppo to break President Bashar al-Assad's siege of the embattled eastern section of the city.
At least 15 civilians were killed as hundreds of missiles have been fired into western Aleppo by rebels, the British-based Syrian Observatory for Human Rights said.
"To our steadfast people in Aleppo, your brothers ... are determined to break the siege of Aleppo," a spokesman for the Ahrar al-Sham rebel group, which is participating in the offensive, said. "We are at the gates, and we will break the siege again."
Rebel forces joining the offensive also include Jabhat Fateh al-Sham -- formerly the al-Nusra Front, a former al-Qaida affiliate.
The Guardian reported rebel forces marched onto Assad-controlled territory after artillery and rockets were fired. About 275,000 people have been besieged by Assad's regime in east Aleppo for months while the Syrian air force and Russian military have increased airstrikes in the area.
Assad and Russia have been accused of committing war crimes due to their bombardment of eastern Aleppo, due to a large number of civilian deaths. Russia and Syria this week were accused of carrying out an airstrike in Syria's Idlib province in which at least 28 civilians -- mostly schoolchildren -- were killed.
Russia's military has since stopped bombing east Aleppo, and Russian President Vladimir Putin on Friday refused commanders' request to resume the strikes due to increased militant activity.
"The Russian president considers it inappropriate at the present time to resume airstrikes in Aleppo," spokesman Dmitry Peskov said.
Peskov, though, added that Russia reserves the right to resume bombings if the circumstances call for it.