Pakistan says its security forces have shot dead a leading member of al-Qaeda in the southern province of Sindh.
Amjad Farooqi (alias Hussain) was one of Pakistan's most wanted men
Officials named him as Amjad Farooqi, wanted in connection with assassination attempts on Pakistan's president and the murder of US reporter Daniel Pearl.
They said he was killed in a four-hour gun battle at a house in Nawabshah, 200 kilometres (125 miles) from Karachi.
"I can confirm that Amjad Farooqi has been killed," said Information Minister Sheikh Rashid.
He said three important terror suspects had also been arrested.
At least three men were killed in the shoot-out, officials said.
Pakistan has recently increased its campaign against Islamic militants.
Interior Minister Aftab Ahmed Khan Sherpao told AP news agency that three Pakistani men arrested in the operation were "possibly involved in terrorist activities inside the country".
"We can't confirm their identities yet," he said.
Amjad Farooqi, also known as Amjad Hussain had a 20 million rupee ($330,000) price on his head.
Security officials described him as an "extremely
intelligent and elusive terrorist operative," who had set up militant cells which worked independently from each other.
He is said to be a close associate of Abu Faraj al-Libbi, described as the operational chief of al-Qaeda in the region, who is also wanted in connection with the assassination attempts on President Pervez Musharraf.
The gunmen put up a "very strong" fight, firing at security officials with automatic weapons, an official told AFP news agency.
Another official said one of the gunmen killed said he would prefer death to arrest and had pointed to the sky, shouting: "I fulfilled my promise to Allah".
Two attempts were made to assassinate President Musharraf last December.
In one, a bridge was blown up as he travelled to his official army residence in Rawalpindi. In the other, suicide bombers driving cars packed with explosives tried to ram his motorcade.
Amjad Farooqi once maintained close contacts with Khalid Sheikh Mohammad - al-Qaeda's alleged number three figure, who was arrested near Islamabad last year.
He was also indicted for involvement in the kidnapping in 2002 and subsequent beheading of Wall Street Journal reporter Daniel Pearl.