Syrian state television says a bomb has exploded near a hotel used by United Nations observers in Damascus, wounding three people.
The report said the blast Wednesday was caused by a bomb planted on a fuel truck.
U.N. officials did not immediately comment, but none of the wounded are believed to be U.N. staff.
The U.N. Security Council is due to discuss the situation in Syria on Thursday, days before the observer mission's mandate expires on August 19.
China's official People's Daily newspaper on Wednesday criticized Western nations for talking about the prospect of a no-fly zone of Syria, saying such comments undermine U.N. mediation efforts and harm the unity of the Security Council.
The paper also reiterated China's commitment to a diplomatic solution to the crisis. China has joined Russia in vetoing U.N. Security Council resolutions threatening Syria with sanctions for using heavy weapons against civilians.