Security forces have renewed shelling in Syria, where an Arab League deadline to accept international monitors or face additional penalties passed with no formal response from Damascus.

Activists say security forces conducted raids in the central Homs region on Friday. The Syrian Observatory for Human Rights tells VOA that security forces have killed at least eight people across the country.

The Syrian military, meanwhile. reported on Friday that “terrorists” killed six of its pilots and three other officers. The state-run SANA news agency says the incident took place in the Homs region on Thursday.

The violence occurred as protesters took to the streets in several cities on Friday, demanding the resignation of President Bashar al-Assad. Separately, state-run media reports government loyalists waving Syrian flags and pictures of Mr. Assad rallied to express their “rejection” of the Arab League measure.

The league suspended Syria's membership two weeks ago because of the government's violent crackdown on dissent and President Assad's failure to implement a league plan designed to end the unrest.

League representatives are due to meet again Saturday to discuss possible sanctions on Damascus.

Syria has blamed much of the violence on foreign-backed terrorists and religious extremists.

The United Nations says more than 3,500 people have been killed since March in connection to Syria's anti-government protests.

On Friday, the U.N. Committee against Torture said it had received reports of widespread abuses in Syria, including the torture of children detained by security forces.