SANA news agency quoted a military source as saying army units "confronted armed terrorist groups" trying to get into the Khaldiya neighborhood north of the rebel area in the Old City in the heart of Homs this week.

Thirty seven militants were killed by the army, SANA said on Thursday.

The so-called Syrian Observatory for Human Rights said at least 45 militants were surrounded and killed as they left the old city on Wednesday night and Thursday morning.

The Syrian armed forces have surrounded militants for more than a year in Homs, a center of the unrest in 2011 which turned into an armed conflict after the infiltration of foreign-backed militants in the Arab nation.

They have also pushed back militants from nearby rural areas which had formed part of their supply lines from neighboring Lebanon and allowed the rebels to challenge control of the main highway linking Damascus to Homs, the Mediterranean coast and the north of the country.

Hundreds of militants and terrorists have been killed in a week of fighting by an array of extremists and more moderate militants against an al-Qaeda affiliate in Syria, the Islamic State in Iraq and the Levant (ISIL).

The infighting comes less than a fortnight before planned peace talks in Switzerland aimed at finding a political solution to almost three years of conflict.

According to reports, Western powers and their regional allies - especially Qatar, Saudi Arabia, and Turkey - are supporting the militants operating inside the country.

NTJ/BA