A security academy at Karachi’s airport came under attack on Tuesday, less than 48 hours after an all-night siege by Taliban gunmen at Pakistan’s busiest airport that killed more than 30 people.

A security academy at Karachi's airport came under attack on Tuesday, less than 48 hours after an all-night siege by Taliban gunmen at Pakistan's busiest airport that killed more than 30 people.

"The ASF academy is under attack. There is gunfire," a senior official at the Federal Investigation Agency said, referring to the Airports Security Force.

It was not immediately clear who was behind the latest strike. A Reuters correspondent near the airport of Pakistan's commercial capital heard gunfire and saw at least four ambulances rushing to the scene.

The army said it had deployed troops to the scene where, according to a Pakistani television report, three militants had been surrounded by security forces.

Two gunmen on a motorcycle opened fire on Karachi's airport academy and fled after Pakistani forces retaliated, a spokesman for the Airports Security Force said. The Pakistani Taliban claimed responsibility for the attack.

Separately, a spokesman for the civil aviation authority said Karachi airport had resumed flights after a brief suspension.

Ten Taliban militants disguised as security force members and armed with rocket-propelled grenades stormed the airport on Sunday night, one of the most brazen attacks.

Earlier on Tuesday, Pakistani fighter jets bombed Taliban positions on the Afghan border.