A 29-year-old Tokyo taxi driver was seriously injured last weekend when he accidently set off an explosive he allegedly planned to send to his girlfriend, police said Thursday.

Police said the man, whose name was withheld, suffered a broken leg and other injuries last Saturday at the taxi company's dormitory in Setagaya Ward.

The man said he was involved in a love triangle, and he had in his possession a revenge manual and other materials that suggest he planned to hurt his girlfriend, police said.

Police plan to question the man on suspicion of violating the Explosives Control Law after he recovers from the injuries.

According to police, the explosive went off around 5 p.m. while he was assembling the bomb, consisting of gun powder, a coil and metal parts, at his friend's apartment in the dormitory.

Colleagues who heard the explosion entered the room immediately and found metal pieces scattered throughout the room, they said.

The man told them the explosion occurred while he was trying to take apart fireworks and asked them to call an ambulance.