Philippines police are investigating a deadly bomb attack on a provincial governor whose family was targeted in the nation's worst political massacre two years ago.

Maguindanao Governor Esmael Mangudadatu said in a television interview Tuesday he believes he was the target of the latest bomb attack, which killed two people and wounded six. An improvised bomb made with a 105-millimeter howitzer shell exploded in a parked car as the governor's seven-car convoy was driving past on Monday.

Mangudadatu, who was riding in a bullet-resistant car on his way to a Maguindanao resort to celebrate his birthday, said he was shaken but not hurt. The blast killed a bystander and a local official whose son lost a leg.

A former governor of the southern province is on trial in Manila along with several of his sons and dozens of family retainers, charged with the 2009 massacre of Mangudadatu's wife and several other family members.

A total of 57 people were slain, including at least 31 journalists, as they traveled to register Mangudadatu's candidacy for the governorship.