Manila, Philippines ? The Philippine president ordered a “total war” on terrorists after a bomb exploded Wednesday near a bustling wharf in the southern port of Davao, killing at least 16 people, including two children.

Forty people were injured in the blast, the second in Davao in less than a month. The death toll would have been higher if the nation were not already on high alert for terror acts, officials said.

The government said it was looking for similarities to a March 4 blast that was blamed on a Muslim rebel group. That bombing killed 21 people, including an American missionary, at the city’s international airport. Three Americans were wounded.

That Muslim group, the separatist Moro Islamic Liberation Front, or MILF, condemned Wednesday’s bombing and denied responsibility for the previous one.

Violence continued early today in Davao when gunmen lobbed two grenades and used a machine gun to strafe a Davao mosque, police said. There were no casualties or damage.

Davao is a predominantly Roman Catholic city on southern Mindanao island, home to a decades-old Muslim insurgency that has claimed hundreds of lives in recent months, including dozens in bombings and ambushes.

The attacks come at a time of debate over the mandate of U.S. troops in the war on terror in the Philippines, where Muslim insurgents have battled the government for decades.

Although President Gloria Macapagal Arroyo is one of Washington’s biggest supporters in the war on terrorism, she has ruled out a combat role for American soldiers.

Arroyo planned to go ahead today with a scheduled visit to Davao. But she said the city was “in a state of lawless violence” and she would order the military to help police crack down on “lawless elements and terrorists.”

Police chief Supt. Isidro Lapena said initial investigations indicated the bomb was stashed in a barbecue food stall.

“We think the security at the pier worked because the attackers were not able to bring the explosive inside,” Lapena said.