The Pakistani Taliban has claimed responsibility for an assault on Karachi airport that has killed 29 people, and given warning that more attacks are on the way.
Besides the dead, at least two dozen people were wounded and flights were suspended as a result of Monday's attack on Jinnah International Airport, which is Pakistan's busiest.
A spokesman for the Tehreek-e-Taliban Pakistan (TTP) said the attack, which began after midnight, was in retaliation for the treatment of TTP prisoners, for air raids in North Waziristan and for the death of Hakimullah Mehsud, who was killed in a drone strike last year.
In a statement posted on Twitter, the armed group said: "We have yet to take revenge for the deaths of hundreds of innocent tribal women and children in Pakistani air strikes. It's just the beginning, we have taken revenge for one, we have to take revenge for hundreds."
Al Jazeera's Kamal Hyder, reporting from Islamabad, said the TTP's Shahidullah Shahed sent a text message confirming responsibility and motive.
The raid involved heavily armed attackers disguised as security personnel, who hurled hand grenades and fired automatic weapons as they targeted the airport's cargo terminal.
The army said it had regained control of the airport around dawn after a six-hour siege, but explosions and shooting could still be heard on Monday morning and Pakistani troops relaunched their operation.
The dead included at least 10 of the attackers, officials said.
Al Jazeera's Hyder said the assault was well-planned, with the attackers "wearing uniforms of the airport security force and using fake IDs" to enter the terminal.
Most passengers were evacuated to a secure location overnight and all local and international flights were suspended, officials said.
However, witnesses told Al Jazeera that more than 60 people were stranded in the main international airport terminal for several hours as they waited for security clearances.
The gun battles went on for several hours, and television pictures showed a large fire raging at the airport as ambulances ferried casualties away.
Officials showed pictures of weapons used in the raid including sub-machine guns, rocket-propelled grenades, grenades and explosives.
Our correspondent said the terminal - an old facility normally used for VIP and cargo flights - was targeted by the attackers before they could gain access to the airport's tarmac.
"This is not the first time. There have been two major attacks in the past, one in Karachi and another in Kamra airbase [in Attock district in Punjab]. There was another attack on Peshawar airport which was foiled," Hyder said.
Security was ramped up at airports and military installations across Pakistan following the Karachi assault.
In a separate incident on Sunday night, at least 23 people including Shia pilgrims were killed in a gun and suicide attack inside a restaurant in Taftan, a town near the Pakistan-Iran border.