Activists say a car bomb near a military airport in Damascus has killed 10 Syrian soldiers and wounded 10 others.
The Britain-based Syrian Observatory for Human Rights said the bomb Monday targeted a checkpoint near the Mazzeh military airport in an upscale neighborhood in western Damascus.
The latest violence comes a day after Russian President Vladimir Putin warned Western nations to be careful in arming Syrian rebels.
Putin gave the warning in London on his way to the G8 summit in Northern Ireland. The Russian leader asked why it is necessary to arm those who he said tear open their enemies and eat their organs, referring to a recent video showing a rebel fighter appearing to cut out an organ from a dead Syrian solider and then bite into it. Putin made the comments standing next to British Prime Minister David Cameron during a news conference.
The United States said last week it has obtained proof that Syria used chemical weapons and will now send direct military aid to the rebels. Washington has not specified what that aid will be. Russia has been sending weapons to the Syrian government but says it is only fulfilling contracts.
Russia and the United States have been working together on planning an international peace conference for Syria, but a time and place are still not set.
The United Nations said the civil war in Syria has killed about 93,000 people over the last two years. Most of those killed have been civilians.
Some information for this report was provided by AP and AFP.
This citizen journalism image provided by Lens Young Homsi shows buildings damaged by fighting between rebel fighters and Syrian government forces in Homs province, Syria, June 18, 2013.
Free Syrian Army fighters fire back during what activists say were clashes with forces loyal to Syria's President Bashar Al-Assad, in Deir al-Zor, June 17, 2013.
A man walks along a street filled with debris in Deir al-Zor, June 17, 2013.
Members of the Free Syrian Army react as they fire a rocket in Deir al-Zor, June 16, 2013.
A man belonging to forces loyal to Syria's President Bashar al-Assad stands next to spent ammunition rounds in Tal El-Tineh village outside Aleppo, Syria, June 16, 2013.
Forces loyal to Syria's President Bashar al-Assad are seen in Tal El-Tineh village outside Aleppo, Syria, June 16, 2013.
Ammunition and an abandoned military truck belonging to forces loyal to President Bashar Al-Assad is seen after clashes in Raqqa province, eastern Syria, June 16, 2013.
Residents are seen as forces loyal to Syria's President Bashar al-Assad enter Ain-Assan village outside Aleppo, Syria, June 15, 2013.