KAUSWAGAN, Lanao del Norte--(UPDATE) A bus driver was killed while three others were wounded when armed men attacked a passenger bus along the highway here Sunday dawn.

Senior Insp. Nestor Ortiz, the provincial police chief, said the Rural Transit bus was on its way to Zamboanga City from Cagayan de Oro when flagged down by armed men in the village of Kawit Oriental at around 2 a.m.

The assailants then shot the driver, Alex Sabang, in the head. But before they could rob passengers of valuables, responding policemen arrived, Ortiz said.

An initial wire report, quoting owners of the bus firms, had said that five were killed.

Before withdrawing, the gunmen fired an M203 mortar at the bus, wounding passengers Persia Catherine, Leny Lahoy and Alcher Itac.

Col. Antonio Supnet, chief of the Army's 104th Brigade, said he dispatched his troops to pursue the armed men.