At least seven people were killed and 15 injured on Tuesday as a blast hit the Police Club in Damascus district of Masaken Barzeh, a source said.A booby-trapped car ripped through the parking lot of the Police Club in Masaken Barzeh, Xinhua quoted the source as saying.Meanwhile, the Syrian Observatory for Human Rights said the explosion killed eight policemen and injured 20 others.The death toll was likely to rise as many of the injured were in critical condition.