* Aircraft bomb stronghold of Pakistani Taliban leader Mehsud
* U.S. officials see Pakistani operation in South Waziristan * President Zardari vows "war to the end"
By Augustine Anthony
ISLAMABAD, June 13 (Reuters) - Pakistani warplanes struck a stronghold of Pakistani Taliban leader Baitullah Mehsud on Saturday, hours after President Asif Ali Zardari vowed to wage war against militancy "to the end".
U.S. officials, thankful that their nuclear-armed ally has gone on the offensive to stop the Taliban tide sweeping across the northwest, said they believed an operation had begun against Mehsud’s forces in the South Waziristan, at the southeast extremity of the tribal belt bordering Afghanistan.
"We will continue this war to the end," Zardari said in a televised address to the nation broadcast in the early hours of Saturday morning.
Under pressure in their sanctuaries, Islamist militants have responded with a wave of bomb attacks in Pakistani cities, including one on Tuesday that killed nine people and devastated the top hotel in Peshawar, the main city in the northwest.
In the past few days the Pakistani military has expanded its theatre of operations, and launched strikes on Taliban fighters across the northwest, most notably in Bannu district at the gateway to the Waziristan region, where according to the military more than 130 militants have been killed since Tuesday.
The military says around 1,300 militants have been killed in Swat and adjoining areas since the army swung into action in late April. Independent casualty estimates were unavailable.
Rising violence has raised fears for Pakistan’s stability and for the safety of its nuclear arsenal but the offensive in Swat has reassured the United States, which needs its Muslim ally’s support to defeat al Qaeda and stabilise neighboring Afghanistan.
On Thursday, the U.S. House of Representatives approved tripling aid to Pakistan to about $1.5 billion a year for five years to help combat extremism through development. Pakistan is now the biggest recipient of U.S. aid.
WAZIRISTAN OPERATIONS UNDERWAY
The airstrike on Makeen village came amid expectations of an imminent military offensive in South Waziristan, as the army enters the final stages of a campaign to rid the Swat valley, northwest of the capital, of Taliban.
"Four fighter jets bombed parts of Makeen early on Saturday but we don’t know about the extent of damage or any casualties," said Mohammad Khan, a shopkeeper in the village.
The bombs killed seven militants and wounded five, according to two intelligence officials in the area who requested anonymity.
Artillery also pounded militant positions in Mehsud territory overnight after a fort at Siplatoi came under rocket fire, according to intelligence officials in the area.
A U.S. official said the Pentagon anticipated combat operations against the Mehsud network, blamed for many of the suicide attacks in Pakistan, including the assassination of Zardari’s wife, former prime minister Benazir Bhutto, in December 2007.
"We are pleased that this level of force is being contemplated," said the official, on condition of anonymity.
Al Qaeda leader Osama bin Laden passed through Waziristan on his escape from Afghanistan in late 2001.
The Pakistani military began combat operations in Waziristan in early 2004, but struck controversial peace deals with militants after each short-lived campaign.
The military has used its air power in other parts of the northwest over the past few days.
On Saturday warplanes bombed militant hideouts in the Mohmand tribal region, killing at least seven people, a paramilitary spokesman in the region said.
And in Bajaur, at the northeasterly end of the tribal belt, air strikes and artillery shelling killed nine militants, intelligence officials said.
In the latest retaliatory attacks by militants, a prominent anti-Taliban cleric who had condemned suicide bombings was killed on Friday in a suicide attack in Lahore, the capital of Punjab province. Two other people were killed and 11 wounded.
Also on Friday, four people were killed and more than 60 were wounded when a car bomber attacked a mosque next to an army depot in the northwestern garrison town of Nowshera.
On Saturday, militants attacked a police bus in Kohat, killing one policeman and a passer-by and wounding nine police.
(Reporting Hafiz Wazir, Aizaz Mohmand, Sahibzada Bahauddin, Alamgir Bitani and Haji Mujtaba; Writing by Simon Cameron-Moore; Editing by Sanjeev Miglani)