Syrian forces fired mortars and rockets into neighborhoods in the country's third-largest city for the sixth consecutive day. Homs is the epicenter of an 11-month-old uprising that has brought the country closer than ever to a civil war.
The assault on Homs began after reports that army defectors and other armed opponents of President Bashar Assad were setting up their own checkpoints and taking control of some areas. The reports could not be confirmed.
The Syrian government blamed the unrest on a foreign conspiracy by Israel and the West, saying armed gangs and terrorists were behind the uprising, not protesters seeking democratic change.
The Arab League says it plans to send observers back into Syria and has raised the possibility of a joint mission with the United Nations.
Last month, the Arab League suspended its monitoring mission because of security concerns.
The Associated Press contributed to this report.