Heavily armed attackers stormed the international airport in Karachi, Pakistan's largest city, late Sunday night, prompting a gun battle that left at least five security personnel dead, officials said.
Four of the attackers also died during an hours-long firefight with security forces at Jinnah International Airport that sent travelers running for safety as gunfire and explosions were heard into the early hours Monday.
Pakistani security officials said they believed about 10 people participated in the assault. By early Monday, Pakistani commandos had confined the remaining attackers to one part of the airport and evacuated all travelers to safety, said Asim Bajwa, spokesman for Pakistani security forces.
There were no immediate reports of casualties among civilians.
Television news footage showed at least one parked plane on fire, and officials said the attackers fired bullets into three aircraft.
Airport officials said that passengers and airline staff had been evacuated from the airport.
Police officials said that the attackers, who were wearing masks and airport security uniforms, raided the airport from three sides in a coordinated assault shortly before midnight, hurling hand grenades and firing heavy weapons.
Pakistani army troops and commandos surrounded the airport as civil aviation authorities issued an alert to all air facilities in the country. All flights into and out of Karachi were suspended.
Munir Sheikh, a senior police official in Karachi, said that Pakistani forces had secured the airport and cornered the attackers in one building. Witnesses and social media accounts reported that firing could still be heard.
"A heavy contingent of security officials are deputed to ensure security of passengers," Sheikh said.
Eyewitnesses said the attackers were wearing suicide vests and carrying heavy ammunition.
"They entered the airport and started firing straight at the security officials. We hid just to save ourselves," one young man told Pakistan's Express News channel.
Another witness, an employee of a private company at the airport, told the channel that three of the attackers "looked like Uzbeks and Chinese. They were not local. They were wearing suicide jackets and had a lot of ammunition with them. They went toward the runway while firing."
The channel did not identify the witnesses.
The gunmen entered the airport through the old terminal, which is generally used by charter flights and passengers embarking on the hajj, the Muslim pilgrimage to Mecca, Saudi Arabia. The airport, Pakistan's busiest, is used by international carriers including Emirates, Cathay Pacific and Thai Airways, and several Pakistani and regional carriers.
An Airbus A-310 passenger jet belonging to Airblue, a Pakistani commercial carrier, was reportedly on fire as television images showed smoke billowing from a jetway where several aircraft were parked.
Karachi, Pakistan's commercial capital, has long been a target of militant attacks. A cease-fire between the government and the Pakistani Taliban, a federation of insurgent groups, expired in April after a failed bid to launch peace talks.
No group claimed responsibility for the attack, but suspicion immediately fell on the Pakistani Taliban, which has carried out attacks on military and civilian targets in recent months in what it has called retaliation for Pakistani strikes on its hide-outs in the country's tribal areas.
"Only organizations like Al Qaeda and the Pakistani Taliban have the capability to carry out such attacks, and both have a presence in Karachi," said a security official in Karachi who requested anonymity because of the sensitivity of the situation.
In a separate incident Sunday, suicide bombers attacked a hotel where Shiite Muslim pilgrims were staying in the volatile Baluchistan province, killing at least 23 people, according to provincial officials. No group claimed responsibility in that incident, either, although attacks on minority Shiites in Baluchistan have often been carried out by sectarian militias that are distinct from the Pakistani Taliban.