Defence secretary Orlando Mercado said he had ordered the military to deploy troops "if necessary" and restore peace in a 729-hectare (1,800-acre) mining complex on Mount Diwalwal.

The mountain in Compostela Valley province, 900 km (560miles) South East of Manila, has been the site of a scramble for gold among Filipinos since the late 1970s.

"There will be no end to this. The fight for gold goes back to Biblical times," Mercado said.

Two local companies are fighting for the right to mine the complex and the dispute has erupted into violence.

On September 3, three miners were burned to death and eight injured when one group allegedly poured gasoline into a tunnel being mined by its rivals and then threw dynamite into it, setting off an explosion, police said.

Twelve workers were injured in a similar tunnel explosion on Wednesday, police operations chief colonel George Aquisap said.

"We have stopped the mining activities and provide security in the tunnels so that no worker, no supplies, no nothing will enter the tunnel," Aquisap said by telephone.

He said the mines bureau was calling a meeting of rival claimants to settle the dispute.

Gold fever proves fatal

Over the years, hundreds are believed to have died in mountainside cave-ins as tens of thousands of poor folk flocked to Diwalwal, caught by the "gold rush" fever.

Many were content with simply panning for gold, satisfied with whatever nuggets they could scoop up on the mountainside.

Others, with more moneyed financiers, went into tunnelling in the search for gold veins.