A convoy of several trucks carrying aid has entered a Syrian town blockaded by pro-government forces and two villages besieged by insurgents for the second time this week, a monitoring group and state media said on Thursday.

Britain-based Syrian Observatory for Human Rights said that aid trucks have started entering rebel-held town of Madaya near the border with Lebanon and the Shiite villages of Kefraya and al-Foua in Idlib province in the northwest of the country.

Syrian state media said six trucks have entered Madaya.

A spokesman for International Committee of the Red Cross said earlier on Thursday that 44 aid trucks were heading to Madaya, and 21 others to Kefraya and al-Foua. The trucks were mainly carrying wheat flour and hygiene products.

"According to the ICRC team that entered Madaya, the people were very happy, even crying when they realized that wheat flour is on the way," Dominik Stillhart, ICRC director of operations, told reporters in New York.

The convoys heading to the towns in the north are currently being checked in Idlib city. So far eight trucks out of 17 have been checked by the insurgents.