ISLAMABAD, Pakistan — Militants launched a brazen attack on Karachi's international airport Sunday night, killing at least 11 people and seizing control of part of the airport in Pakistan's largest city for more than five hours.
The well-coordinated attack involved 10 assailants who were armed with grenades, rocket launchers and assault weapons, authorities said. Some of them were also said to be wearing suicide vests. They battled Pakistani security forces through the night before all the assailants were slain, officials said.
Several large fires broke out at the airport, but all airline passengers escaped unharmed, according to a Pakistani army spokesman.
But the siege, one of the worst security breaches at a Pakistani airport, is raising serious questions about the country's ability to protect its major transit hubs amid the persistent threat of terrorism. The attack comes as Prime Minister Nawaz Sharif and the country's military have been considering a major offensive against the Pakistani Taliban, which has been waging a bloody insurgency.
"This act of terror is unforgivable," Khawaja Muhammad Asif, Pakistan's defense minister, told local television reporters. "The state will give an appropriate response to such cowardly acts of terror. Those who plan and those who execute the terrorist attacks will be defeated."
There was no immediate assertion of responsibility for the attack.
It was unclear how such an assault could occur at what is supposed to be a heavily fortified airport. The attack, which began at 11 p.m. and lasted until dawn, is likely to be another blow to Pakistan's efforts to lure international business to help its struggling economy.
"I would not want to send any nonmilitary, non-law-enforcement personnel into that area at this moment," Terrance Gainer, a security consultant and former chief of the U.S. Capitol Police, said in an interview. He said U.S. security and antiterrorism officials would undoubtedly be scrutinizing the attack to learn how it occurred.
According to preliminary information from Pakistani security officials, the attack began when about five assailants gained access to Jinnah International Airport, apparently shooting their way through a gate near the old terminal. At least five others entered separately; they may have blasted their way through a wall near the cargo area, officials said.
Amjad Shah, a Karachi police official, said at least some of the militants were wearing uniforms used by security forces.
Once inside, the militants began lobbing grenades and took up positions near the runway and in the airport's cargo area. One senior Pakistani intelligence official, who spoke to the Washington Post on the condition of anonymity to discuss security issues, said some of the militants intended to hijack a plane but were unsuccessful.
All arriving flights were quickly diverted from the airport, which serves 6 million passengers annually. Three international flights were scheduled to leave between 11 p.m. and 1 a.m., going to Sharjah, United Arab Emirates; Bangkok; and Dubai. But all passengers at the airport were evacuated safely, according to Maj. Gen. Asim Saleem Bajwa, the spokesman for Pakistan's military and security agencies.
About 90 minutes after the attack began, hundreds of Pakistani army commandos arrived on the scene and began battling the militants.
Hospital officials said that at least 11 people were killed by the assailants — eight airport security personnel, a Pakistan International Airlines employee, a police sub-inspector and an official with Pakistan's Civil Aviation Authority.
About 5 a.m. today, Bajwa reported that the siege had ended after all the attackers were killed. Bajwa said that eight of them were shot and that two blew themselves up once cornered.