Updated

A bomb attached to a parked motorcycle exploded Sunday in a violent southern Philippine province, wounding two people and narrowly missing the convoy of a mayor belonging to a powerful clan blamed for a massacre last year of dozens of people, officials said.

The bomb constructed from a mortar round went off near a grade school in Maguindanao province's Shariff Aguak town a few minutes after the convoy of Mayor Akmad Ampatuan of nearby Datu Salibo town passed by, police said.

The bomb, which wounded two residents, appeared to have been meant for Ampatuan, police said.

Several members of his clan and armed followers have been put on trial in connection with the massacre in Maguindanao last Nov. 23 of 57 people, including political rivals and at least 30 media workers.

Police said other political rivals may have been behind Sunday's blast, adding that there was no sign it was related to the massacre.

Many members of the Ampatuan clan still wield power in Maguindanao, an impoverished province 560 miles (900 kilometers) south of Manila that has been wracked by a decades-old Muslim secessionist conflict.