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.