A blast flattened a house being used by militants in Pakistan's financial capital Karachi on Friday, with eight people killed when explosives apparently detonated accidentally, police said.
Guns, grenades and suicide vests were recovered from the house in a poor Karachi neighbourhood, which officials said was a den for Islamist insurgents waging an escalating campaign of violence across the nuclear-armed nation.
In a separate incident in northwest Khyber district, five militants were killed when a suicide bomber from a rival Islamist militia blew himself up.
Attacks have intensified as Pakistan's military -- with vocal support from Washington -- pushes into northwest Taliban strongholds. Karachi suffered its worst attack in two years when a bomb killed 43 people in December.
Fayyaz Khan, a senior police official in southern Karachi, said eight people were killed in Friday's early morning house blast.
"We have pulled out all the eight bodies from the rubble and shifted them to hospital for the autopsies," he said.
Another police official, Abdul Majeed Dasti, said grenades, a Kalashnikov rifle and suicide vests were found at the scene, while city police chief Waseem Ahmad said the explosives appeared to have been detonated unintentionally.
"It seems that explosives which were stored in the house caused the explosion... The house was being used by terrorists," Ahmad said, adding that two people had been arrested at the scene.
Interior Minister Rehman Malik told reporters the people living in the house were from Swat, a northwestern district where the military launched an operation last year to quash a two-year uprising by Taliban fighters.
Suicide bombings and attacks by the Taliban and other Islamist militant groups have intensified in recent months as the military pursues an aggressive offensive to quash insurgent strongholds near the Afghan border.
Karachi had until recently been spared the worst of the bloodshed, then on December 28 a bomb ripped through a procession of Shiite Muslim worshippers, killing 43 people and turning their holy day of Ashura into a bloodbath.
The victims of Friday's blast appeared to be residents of the rented house, officials said.
In Khyber tribal district, meanwhile, five people was killed and 12 wounded when a suicide bomber blew himself at the offices of a rival militant group, top local administration official Shafeerullah Khan told AFP.
"The bomber blew himself up when stopped by a security guard from entering the headquarters of militant group, Ansar-ul-Islam," Khan said.
"This was a suicide attack on Ansar-ul-Islam headquarters in which five militants belonging to the outfit were killed."
Ansar-ul-Islam (Companions of Islam) is a rival of Lashkar-e-Islam (Army of Islam), the main militant group staging attacks in Khyber, which borders Afghanistan.
More than 2,900 people have been killed in attacks in Pakistan since militant violence intensified in July 2007.
Although Karachi, a cosmopolitan port city far away from the troubled northwest, sees fewer attacks, there are fears militants are using the cover of a city of about 14 million people to regroup and plan attacks.
Islamist militants say their campaign is to avenge the military offensives and Pakistan's unpopular alliance with the United States in the eight-year war against the Taliban in neighbouring Afghanistan.
Washington has praised Pakistan's action against the Taliban but is urging the country to also crack down on militants who hide out in the lawless northwest and cross the border to attack NATO and US troops in Afghanistan.
The two nations are also at odds over increasing missile strikes by unmanned US aircraft targeting high-level militants in Pakistan's northwest.
Speaking during a visit to Islamabad on Friday, US Republican Senator John McCain defended the attacks as necessary to protect troops in Afghanistan.
"Friends don't always agree on every issue but we certainly are in agreement on a common goal, and we also face a common enemy," he said.
"The enemy of radical Islamic extremism, that wants to destroy everything that we stand for and believe in."
Copyright 2010 AFP South Asian Edition
