The Associated Press says a human rights activist and a resident are reporting intense gunfire as Syrian security forces conduct raids and arrests in a restive central city that has experienced some of the worst violence in the past week.

Rami Abdul-Rahman, the director of the London-based Syrian Observatory for Human Rights, says tanks have closed on some neighborhoods in Homs including Bab al-Sebaa, where the main raids are taking place.

A resident in the city, says mosque loudspeakers are calling for people to aid Bab al-Sebaa. The resident, who spoke on condition of anonymity for fear of government reprisals, says the neighborhood has been subjected to heavy machine-gun fire since 4am on Thursday.