Three suicide bombers blew up their explosives-laden van when they were challenged by police on the seafront of Karachi in southern Pakistan on Wednesday, killing two policemen.
The three terrorists were travelling in the explosives-laden van when police asked them to stop in seaview area of Karachi at about 10 pm.
The men were killed when they detonated the explosives in the van, Superintendent of Police Tariq Dharejo told the media.
"Police tried to stop the vehicle and they blew themselves up. The three men were killed and we have found weapons at the spot... One of the men was wearing a (suicide) vest," Dharejo said.
Two policemen, who were chasing the van on a motorcycle, were wounded by the blast.
Both of them succumbed to their injuries later, police officials said.
The blast occurred in an uninhabited area along the seafront located a short distance from a park and a restaurant.
"The policemen were chasing the Suzuki high-roof and exchange of fire took place and after a chase the men in the car apparently detonated themselves resulting in the blast," an official said.
The bombers may have been planning to target a hotel or a 'mela' (fair) to be held in the area, officials said. TV news channels said intelligence agencies had warned of a possible attack with an explosives-laden vehicle in Karachi.
Footage on television showed the body of one of the alleged terrorists, a bearded man wearing a shalwar-kameez. The bloodied body lay a short distance from the mangled debris of the van, which was destroyed by the blast.
Police found several suicide vests, grenades, night vision goggles, AK-47s, a wig and a burqa in the wreckage of the van, officials said.
A bomb disposal squad was called in to defuse the suicide vests and grenades.
The wig and burqa apparently gave rise to speculation that a woman was present in the van with the terrorists.
This is the second suicide blast in the same area in Karachi. On September 19, terrorists rammed an explosive-laden truck into the residence of a senior police official of the anti-terrorism wing, killing eight people.