Karachi: Two men, believed to be potential suicide bombers, were killed when the explosives they were carrying on a motorcycle exploded in this restive Pakistani city on Tuesday.

Police said the bomb exploded as the motorbike slipped at Abu Isfahani road, killing both the men.

He said two other men who were passing through the area were injured after they were hit by the shrapnel of the explosive device.

Experts from the bomb disposal squad said the two men were carrying the explosives to be used in a 'terrorist act' to another area in Karachi.

A police officer said that preliminary investigation suggests that the two men were would-be suicide bombers.

The motorcycle was completely destroyed and the blast also damaged a car.

Rescue teams collected body parts that were scattered in the area after the explosion.

Karachi has been in the grip of a wave of violence in recent weeks and its police chief told the Supreme Court that ethnic and sectarian attacks have claimed 306 lives in a month.