Three suspected Pakistani militants were blown to pieces by their explosives on Saturday when they rode over a bump on a bicycle outside a town in the central province of Punjab, police said.
"The head of one man has been blown off," Deputy Superintendent Bashir Ahmed told the agency from Chichawatni, a town some 120 km north of Multan, the main city in southern Punjab.
Another of the dead men had his legs blown off, while the third had his stomach ripped open and died later in hospital, police said.
At least two of the dead men were students at a nearby madrasa, suspected of having links to Sipah-e-Sahaba Pakistan, a banned Sunni Muslim sectarian group, according to Ahmed.
Pakistan is in the grip of a nationwide security scare having suffered a series of suicide bomb attacks in recent weeks, and police have also arrested several would-be suicide bombers.
Suicide bombers have killed over 40 people since mid-January in cities around the country.
Factions of a Sunni Muslim sectarian group, Lashkar-e-Jhangvi, with close links to Al-Qaeda are suspected of being behind a number of the attacks.
Intelligence officials have also thrown suspicion on Pakistani Taliban militants as the spate of bomb attacks followed a military air strike on one of their bases in the restive Waziristan tribal region bordering Afghanistan.
Police were unsure what kind of attack the men on the bike were planning.
"We don't know whether they wanted to carry out a suicide attack or plant the explosives somewhere," Ahmed said, adding that initial investigations suggested the explosive was home-made.