PESHAWAR: Pakistani troops Wednesday took control of the key town in northwestern Buner district, a day after launching a major ground and air assault against Taliban militants, the military said.

"We have taken control of Dagar town and an operation by the ground forces is under way," a senior military officer told AFP.

"Early morning Wednesday, heliborne forces successfully landed at Dagar and surrounding areas and secured Dagar, headquarters of Buner district," the military added in a statement.

The army and paramilitary Frontier Corps troops were involved in the operation. Residents said helicopters were seen shelling suspected hideouts in the surrounding mountains.

Pakistan troops launched an operation in the Buner district near the Swat valley on Tuesday, in an intensified effort to flush out Taliban militants.

Chief military spokesman Major General Athar Abbas said fighter jets had also been used in the operation.

Dagar, a town of about 25,000, is the administrative centre of Buner.

The latest operation by the Pakistani military follows an offensive mounted in nearby Lower Dir over the weekend that has swelled the number of people displaced by fighting in northwest Pakistan, prompting calls for humanitarian help by local officials and aid workers.

The United States, which has put Pakistan at the heart of the battle against terrorism and Al-Qaeda, hailed the military operations as "exactly the appropriate response" to halt the Taliban's progress, Pentagon spokesman Geoff Morrell said.

"We are encouraging of these efforts," Morrell said. "We hope they can sustain these operations." The offensive mounted in Lower Dir, in which 70-75 militants and 10 security personnel died, has now been completed, Abbas said on Tuesday.

The operation in Buner has been mounted to stem Taliban efforts to encroach into regions beyond Swat.

In February, the government agreed that Islamic sharia law could be enforced in Swat and its surrounding districts in the region in a deal aimed at ending two years of rebellion during which followers of radical cleric Maulana Fazlullah beheaded opponents and torched girls' schools.

But up to 500 Taliban entered Buner earlier this month in what the military said was a "violation" of the February agreement.

Taliban reacted bitterly to the government operation saying that the militants were resisting and "reserve the right to retaliate." They said the Swat deal remained intact until abrogated by the elderly cleric Sufi Mohammad, who had negotiated it. "We are still abiding by the agreement. But if it is revoked by Sufi Mohammad, we will resume our Jihad (holy war) against the government like in the past," Muslim Khan, a spokesman for Swat Taliban, said. "The operation is an act of extreme tyranny in which women and children are being targetted," he said, adding that "it is drama being staged by the government to justify billions of dollars it received from America." The Taliban's advance was branded by Washington as "an existential threat" to Pakistan and US Secretary of State Hillary Clinton warned that it was "basically abdicating to the Taliban and to the extremists".