Shells of unknown origin fell in the vicinity of Syria's Mezzah military airport in the capital Damascus on Tuesday, the state-run Al Ekhbariya TV reported.
Syria's state news agency earlier reported the sound of an explosion in the vicinity of Damascus and said the matter was under investigation.
Reuters reported in November that Washington was planning to establish a military presence at an airbase in Damascus to help enable a security pact that Washington is brokering between Syria and Israel.
The airbase sits at the gateway to parts of southern Syria that are expected to make up a demilitarised zone as part of a future non-aggression pact between Israel and Syria.
A Syrian foreign ministry source denied the Reuters report, saying it was "false" but without further clarification.
The U.S. has been mediating between Syria and Israel to de-escalate tensions and reach a security pact that Damascus hopes will reverse Israel's recent seizures of its land.
Reporting by Jaidaa Taha and Muhammad Al Gebaly