At least 45 rebel fighters were killed on Thursday in Syria's central province of Homs, the Britain-based Syrian Observatory for Human Rights reportedly said.

The rebel fighters were killed by the Syrian troops while attempting to break the government troops' year-long siege on rebellious districts in Homs, according to the report.

The pro-government al-Khabar TV also reported the incident, saying that tens of rebel fighters were killed Thursday while trying to infiltrate into Homs' al-Khalidiyeh district, which was recaptured by the Syrian troops last year.

The TV said the National Defense Unites, a pro-government paramilitary unit, responded to the attack and killed all of the rebels.

Earlier on Thursday, 18 people were killed in separate mortar attacks in Homs, Syria's third largest city, of which the government accused rebels of being behind.