Rights groups say Syrian security forces killed at least five people on Thursday, as Arab League monitors headed to three key areas where the government has violently repressed opposition.

Activists say some of Thursday's deaths occurred near Damascus after security forces opened fire on anti-government protesters.

The violence took place as monitors prepared to visit the regions of Daraa, Hama and Idlib to check on government pledges to halt the deadly crackdown and release political detainees.

On Wednesday, activists and rights groups said government forces had killed at least 39 people since the monitors arrived Monday, including six people shot in Hama.

Also Wednesday, some residents and activists raised concerns that the Arab observers were neither properly qualified nor independent. Residents of the hard-hit district of Baba Amr in Homs refused to allow observers in because army officers were with them. The standoff ended when the officers withdrew.

Syrian authorities agreed to the Arab League observers under international pressure and threats of Arab sanctions. The plan requires Syrian authorities to give the monitors freedom of movement except for sensitive military sites.

The United Nations estimates 5,000 people have been killed since March in violence linked to Syria's unrest. Syria says armed terrorists are driving the revolt. It accuses them of killing 2,000 security personnel since March.