Troops battled suspected communist guerrillas attempting to burn a passenger bus outside the capital Friday, leaving four people dead, the military said.

The gunfight erupted as a general strike called by leftist unions appeared to have fizzled after two days. The unions are demanding an increase in the minimum daily wage, which is the equivalent of $3.46.President Corazon Aquino said companies cannot afford the raise, which equals $1.48.

One reason workers are calling for more money is to help them cope with higher petroleum costs caused by the Persian Gulf crisis.