A Pakistani Taliban leader blew himself up to avoid arrest by government forces near the Afghan border on Tuesday, three years after his release from US detention in Guantanamo Bay, officials said.
Abdullah Mehsud, 31, spent over 2 years in Guantanamo.
Shortly after his release in March 2004, Mehsud shot to prominence by kidnapping two Chinese engineers working in South Waziristan, a region known as a hotbed of support for Al-Qaeda and the Taliban.
"He was killed in a house in Zhob," Interior Ministry spokesman Javed Iqbal Cheema said, referring to a district of southwest Baluchistan province neighbouring Waziristan.
A counter-terrorism squad acting on a tip-off raided the house belonging to a senior official from the pro-Taliban Islamist party of Fazal-ur-Rehman, leader of the opposition in the National Assembly.
"We asked them to surrender but they opened fire," Mira Jan, the chief administrator for Zhob, told Reuters.
"The shooting lasted for about half an hour and then we heard a blast from inside the house."
Mehsud blew himself to avoid arrest, Jan said. Four other men were arrested.
Mehsud, who lost a leg in a landmine explosion a few days before the Taliban took Kabul in September 1996, was second-in-command of a Pakistani Taliban group headed by Baitullah Mehsud.
Baitullah Mehsud's followers have kept up the fight against US, NATO and Afghan forces deep inside Afghanistan.
The elimination of Abdullah Mehsud comes hard on the heels of a series of clashes between security forces and militants in North Waziristan.
The army says it has killed at least 54 militants since Saturday evening, the same day US President George W Bush said he was "troubled" by intelligence reports suggesting Al-Qaeda was regathering strength in Pakistani tribal areas.
Bush said Pakistan President Pervez Musharraf had realised a peace pact struck with militants in North Waziristan 10 months ago had failed and was taking action.
In Bajaur, the most northeasterly of Pakistan's seven semi-autonomous tribal regions, militants executed two paramilitary soldiers, kidnapped on Monday.
Their bodies were found wrapped in plastic bags and dumped in a field near Khar, the main town in Bajaur.
In March, tribesmen in Bajaur gave the government assurances they would not shelter foreign fighters.
But Islamist militants in the lawless border region have launched several attacks on security forces to avenge the storming of a radical mosque in the capital, Islamabad, this month.
More than 180 people, mostly police and soldiers, have been killed in a spate of attacks, mostly in northwest Pakistan, since the operation against the Lal Masjid, or Red Mosque, complex was launched on July 3.
The government said 102 people were killed in the siege and the storming of the mosque on July 10.