Philippines: Helicopters fire rockets on Muslim rebels
Government forces in the Philippines have begun firing rockets from helicopters in an attempt to dislodge Muslim rebels who have been holding parts of the city of Zamboanga for the past week.
The insurgents say they want to establish an independent Muslim state on the southern island of Mindanao.
Zamboanga has been brought to a standstill by the week-long siege.
An unknown number of civilians are still trapped with the insurgents.
The rebels are from the Moro National Liberation Front, one of a number of splinter groups fighting for independence from Manila.
- Insurgency in the south involving MNLF, MILF and numerous splinter groups fighting for independence largely on racial grounds
- Small hard-line Islamist group Abu Sayyaf known to carry out extremely violent attacks, mostly in south
- Communist rebellion by New People's Army, one of the world's longest-running insurgencies
Analysts say the group's leader, Nur Misuari, is angry because his faction has been sidelined in government peace talks.
The gunmen arrived last Monday in Zamboanga - a city of one million people - by boat, and apparently tried to march on the city hall to hoist their flag.
On Friday government forces launched an assault to regain control. Around 3,000 troops are taking part in the campaign.
Helicopters were brought in on Monday to add to their firepower but the ferocity of the fighting has raised fears for the fate of civilians, reports the BBC's South East Asia correspondent, Jonathan Head.
Fifty-one militants have been killed, according to a spokesman for the military.
Lieutenant Colonel Ramon Zagala said that six members of the security forces and four civilians had died.
The government is no longer talking about negotiating with the rebels and now want to end the battle quickly, and decisively, our correspondent says.