Around 10 gunmen attacked a security checkpost outside Pakistan's Karachi airport on Tuesday, officials said, and were exchanging fire with troops, a day after a siege by the Taliban left 37 dead.

The attack raises further questions about authorities' ability to secure key facilities in the face of a seemingly resurgent enemy, as a nascent peace process with the Pakistani Taliban lies in tatters.

“Gunmen are exchanging fire with Airport Security Force (ASF) personnel at a checkpost guarding the airport,” an ASF spokesman said.

He continued: “They are moving back, we are trying to nab them,” adding that no security forces had so far been hurt or killed.

Another security official at the scene told AFP that the attack involved around 10 militants.

Flights were suspended once more, having resumed following the previous attack.

“We have suspended all flight operations at Karachi airport and we are evacuating passengers,” said Mashud Tajwar, a spokesman for Pakistan International Airlines.

Civil Aviation Authority spokesman Abid Qaimkhani added that incoming flights had been diverted.

The checkpost is located at the entrance of an ASF camp some 500 metres (yards) away from the main airport premises, or one kilometre from the passenger terminal.

An AFP reporter at the scene said rangers, police and army commandos were arriving at the camp, which has little by way of cover and were taking up positions to engage the militants in an open field.

The assault came as Pakistan launched air strikes on a militant-infested tribal district, killing 15 people in apparent retaliation for Monday's assault.

Ten Taliban fighters, some dressed in military uniform and armed with machine guns, grenades and rocket launchers launched the attack on Sunday night.

Their main objective “was to destroy the aircraft on the ground but there was only minor damage to two to three aircraft,” Interior Minister Chaudhry Nisar Ali Khan said late Monday.

The Taliban had vowed the first attack was just the beginning as they sought to avenge the death of their former chief Hakimullah Mehsud. (AFP)