(Adds IMU statement, background)
By Syed Raza Hassan
KARACHI, Pakistan, June 11 (Reuters) - Cathay Pacific Airways has cancelled all flights to the Pakistani city of Karachi from Bangkok following a Taliban raid on the country's busiest airport this week, as top Pakistani officials debated how to tackle the escalating violence.
International flights in and out of Karachi have been suspended twice since Sunday, when gunmen wearing military uniforms stormed the airport, firing rocket-propelled grenades in an all-night siege that killed 34 people.
"We will continue to monitor the situation closely," Cathay said in a statement. "Customers are recommended to check flight status before departing for the airport."
Cathay Pacific shares closed down 0.14 percent at HK$14.48 on the Hong Kong Stock Exchange.
In Islamabad, Prime Minister Nawaz Sharif chaired a meeting with security officials late on Tuesday to discuss how to handle the crisis as the escalation of violence raised the prospects of an all-out army campaign against insurgent strongholds.
The Pakistani Taliban, a loose alliance of insurgent groups united by anti-state Jihadist ideology, said they had carried out the Karachi attack in response to strikes on their positions on the Afghan border.
Adding an international dimension to the events, Pakistani officials said ethnic Uzbek fighters were behind the attack and a report by a Pakistani monitoring website quoted an Uzbek commander as claiming responsibility.
"Usman Ghazi, the leader of the Islamic Movement of Uzbekistan (IMU), claimed responsibility for Sunday's terrorist attack," said the site, Pakistan Risk.
The IMU is a group allied with the Taliban which has often carried out attacks alongside it.
"The Uzbek militant group, which has been based in Pakistan's tribal areas since 2002, describes the attacks as revenge for Pakistani airstrikes in North Waziristan on May 21 that targeted areas populated by Uzbek and other foreign militants," Pakistan Risk said.
Earlier, the Taliban's central command also claimed responsibility for the attack.
Pakistan's air force has periodically bombed Taliban hideouts in the ethnic Pashtun belt straddling the border, but has yet to mount a major ground offensive there.
Security was tight around Karachi airport and the bustling city of 18 million people remained nervous after the twin attacks, though life seemed to have returned to normal, with shops and markets open and people going about daily tasks.
"It looks like the Taliban have taken over the entire country," said Mohammad Gulfam, who owns an electrical appliances shop in Karachi.
"What we want is that the army should carry out a big operation to clear out all the country, so that the public can get some peace of mind."
The Taliban's goal was to scare off international airlines from an airport serving Pakistan's economic and financial nerve centre, said Imtiaz Gul, a security analyst in Islamabad, the capital.
"They (militants) came with a certain design to take an aircraft and passengers hostage and create a scene which would have lasted for many days," Gul added.
"It would have put Pakistan in the international spotlight. That would have meant that foreigners and foreign airlines flying to Pakistani should stop doing that."
Sunday's assault all but destroyed prospects for peace talks between the Taliban and Sharif's government, after months of failed attempts to engage the al Qaeda-linked militants in dialogue on how to end years of violence.
The Pakistani Taliban are allied with the Afghan militants of the same name and share a similar jihadist ideology.
But they operate as a separate entity, focused entirely on toppling the Pakistani state and establishing strict Islamic rule in the nuclear-armed nation, whereas the Afghan Taliban are united by their campaign against invading foreign forces. (Writing by Maria Golovnina Additional reporting by Anne Marie Roantree and Clare Baldwin; Editing by Clarence Fernandez)