The Philippine government is to triple the size of a special forces military unit that operates against armed fighters responsible for bombings and kidnappings of Westerners, officials say.

The Light Reaction Battalion is to be built up to regiment size, Philippine Army chief Lieutenant-General Noel Coballes said on Tuesday, with an increase from about 500 soldiers to as many as 1,500.

"We have seen how effective they are, so we are strengthening the unit in terms of anti-terrorism. From a battalion we'll increase it to a regiment," he said.

The unit is fighting the Abu Sayyaf, a group of several hundred armed fighters who are behind the country's deadliest attacks as well as kidnappings of Western targets.

Voltaire Gazmin, defence secretary, said the battalion had taken substantial casualties during a three-week battle against fighters in the southern port of Zamboanga in September last year.

The fighters were followers of former rebel leader Nur Misuari, who went into hiding as hundreds of his men infiltrated Zamboanga to oppose a proposed peace treaty between the Philippine government and a rival Muslim armed faction.

The fighting left more than 240 people dead and displaced about 116,000 people as entire districts of the city of nearly a million people went up in flames.

"As you have seen, we lost a number of our men in the Zamboanga incident, which led to a shortage that needed to be addressed," Gazmin said.

Neither official gave a timetable, but Lieutenant-Colonel Ramon Zagala, an armed forces spokesman, said the unit would be bulked up within the year.

"Based on what happened in Zamboanga, our military leadership saw a need to increase the strength of the Light Reaction Battalion to be able to address contingencies anywhere in the country," Zagala told AFP news agency.

Source: AFP