Three Pakistani militants blew themselves up after police raided their hideout on Friday, preventing a major attack in the country's biggest city Karachi, police said.
The raid comes less than a week after a suicide truck bomber killed at least 60 people at the Marriott Hotel in Islamabad in one of the worst attacks in Pakistan's history.
"We have saved Karachi from death and destruction. We know who they were and what was their target in Karachi, but we cannot disclose it immediately," provincial police chief Babar Khattak told AFP.
The incident happened hours before Prime Minister Yousuf Raza Gilani was due in the city but there was no official indication that he was the target.
Police launched the raid in Karachi's Baldia neighbourhood based on information provided by an unidentified "high value target", who was arrested at dawn, Khattak said.
"We surrounded the area after the detainee told interrogators that his colleagues hiding there were heavily armed and also carried suicide jackets," Khattak said.
The militants resisted the siege and lobbed at least five grenades at police, but caused no casualties.
"The militants blew themselves up after their ammunition was exhausted," Khattak said.
Khattak said the militants were also wanted in connection with a suicide bombing at a religious gathering in Karachi in which 47 people were killed.