Pakistani soldiers heading towards North Waziristan are pictured by a road in Bannu district on Monday.

MIRANSHAH, Pakistan — The Pakistani Taliban on Monday warned foreign firms to leave the country and vowed retaliatory strikes against the government after tanks, ground troops and jets were deployed in a long-awaited offensive in a troubled tribal district.

The warning came as Pakistan’s major cities braced for revenge attacks by ramping up security at key installations and ordering soldiers to patrol the streets, while hospitals in the northwest prepared for incoming casualties.

The offensive on North Waziristan, a stronghold of Taliban and Al-Qaeda militants, was launched a week after a brazen insurgent attack on Pakistan’s main airport in Karachi which left dozens dead and marked the end of a troubled peace process.

Pakistan’s Western allies, particularly the United States, have long demanded an operation in the mountainous territory to flush out groups like the Haqqani network which use the area to target NATO troops in neighboring Afghanistan.

But authorities had held back from a final push – possibly fearful of angering pro-Pakistan warlords and of opening too many fronts in their decade-long battle against homegrown Islamist insurgents.

The Tehreek-e-Taliban Pakistan (TTP) main spokesman Shahidullah Shahid warned foreign countries to stop doing business with the government and supporting their “apostate army”.

“We warn all foreign investors, airlines and multinational corporations that they should immediately suspend their ongoing matters with Pakistan and prepare to leave Pakistan, otherwise they will be responsible for their own loss,” he said in a statement.

“We hold Nawaz Sharif’s government and the Punjabi establishment responsible for the loss of tribal Muslims’ life and property as a result of this operation,” he added, vowing to “burn your palaces” in Islamabad and Lahore.

The warning came as major cities beefed up their security, with troops seen patrolling the streets of Islamabad, Lahore and Karachi.

“The security of the capital was already on alert, but a new alert has been issued,” an Islamabad police spokesman told AFP.

Police in Pakistan’s economic hub Karachi have declared a “red alert” and cancelled leave for all 27,000 personnel, spokesman Atiq Shaikh told AFP.

And in northwestern Khyber-Pakhtunkhwa province which borders the tribal zone, the government has declared a state of emergency in all hospitals and asked them to prepare for incoming casualties, provincial health minister Shahram Khan Tarakai said in a statement.

Pakistani air force jets have been pounding suspected militant hideouts in the region since Sunday and have been joined by tanks and infantry engaging in heavy artillery strikes.

An AFP reporter in the region’s main town of Miranshah said tanks were now occupying the bazaar as troops fire intermittently in the air to warn people not to leave their homes.

More than 2,000 troops could be seen at new posts set up in the mountains. Pakistan already had troops stationed in the tribal district, but these were reinforced in the days leading up to the offensive.

The death toll from the offensive so far stands at 177, according to the military, the majority through air strikes but some through sniper fire. The figures cannot be verified independently.

In the town of Bannu 10 kilometers (6 miles) east of North Wazirstan, hundreds of military trucks with machine guns installed on top were on their way toward the fighting zone, as were oil tankers and a military field hospital.

At the Kashoo Bridge area, some 25 kilometers northeast of Bannu, tractors were busy leveling the ground to set up a camp for internally displaced people (IDPs).

Arshad Khan, Director General Fata Disaster Management Authority (FDMA) said: “We have made arrangements to accommodate IDPs in two camps.”

Some 62,000 people have fled the region so far into other parts of Pakistan according to official data, with “hundreds of thousands” eventually expected.

The operation, labeled ‘Zarb-e-Azb’, is the latest carried out by the military against insurgents after Pakistan joined the US-led war on terror efforts after 9/11.

The exodus of thousands of fighters across the porous border ahead of the operation, meanwhile, could mean they eventually return, as has been the case in past offensives.