Fresh militant attack near Karachi airport
Security forces at Pakistan's busiest airport in the city of Karachi have come under attack, a day after militants stormed one of its terminals.
Officials say gunmen on motorbikes shot at a security training camp just outside the airport and fled.
Subsequent firing which lasted for up to an hour was shots fired by the army and police at the scene, officials say.
Flights at the airport are resuming. The Pakistani Taliban say they carried out both attacks.
The gun and bomb attack on the airport's cargo terminal on Sunday left at least 38 dead, including the attackers.
Reports say the attack began after militants pulled up a vehicle and began firing. Officials said the gunfire was directed towards their camp, but no gunmen penetrated the airport security perimeter.
The heavy weapons and sustained gunfire seems to have been the concerted army response so close to the scene of the airport attack.
Pakistan's Prime Minister Nawaz Sharif has said the attackers should be "pursued and eliminated".
The military has sealed off the area and are conducting intensive search operations in the area.
Analysis: M Ilyas Khan, BBC News, Islamabad
Pakistanis have reacted in shock to the attacks on Karachi airport and what is being seen as retaliatory bombing of militant hideouts in the north-west by government jets. The Karachi attacks have undermined an atmosphere of peace and rapprochement which Prime Minister Nawaz Sharif had been working to create.
They have also targeted his plans for an early economic recovery by raising big questions over security for international travellers arriving and leaving the commercial capital.
The surge in violence comes amid a growing perception that Pakistani forces may finally be about to launch an operation in North Waziristan to clean up what many here see as the militants' last remaining sanctuary on Pakistani territory.
But the ability of the militants to keep up the tempo will depend on the security of their urban cells, their continued access to "insider" intelligence, and the extent to which Pakistan is willing to part with its traditional policy of classifying militants as "good" and "bad".
Several flights were turned back - one shortly before it was due to land - as they were en route to Karachi, local media reports say.
The death toll from Sunday night's airport raid rose sharply overnight after nine more bodies were discovered, seven of them in a cold storage facility.
This latest violence comes against the backdrop of a major split in the Pakistani Taliban, and threats of retaliation following military operations against Pakistan's tribal north-west.
It has brought the government of Mr Sharif under renewed pressure to order tough action against the Taliban, correspondents say.
Early on Tuesday the Pakistani military carried out air strikes in tribal areas in the north-west Khyber region, killing at least 15 militants, officials say.
Who are the Pakistani Taliban?
• With its roots in the Afghan Taliban, the Pakistani Tehreek-e-Taliban movement came to the fore in 2007 by unleashing a wave of violence
• Its leaders have traditionally been based in Pakistan's tribal areas but it is really a loose affiliation of militant groups, some based in areas like Punjab and even Karachi
• The various Taliban groups have different attitudes to talks with the government - some analysts say this has led to divisions in the movement
• Collectively they are responsible for the deaths of thousands of Pakistanis and have also co-ordinated assaults on numerous security targets
• Two former TTP leaders, Baitullah Mehsud and Hakimullah Mehsud, as well as many senior commanders have been killed in US drone strikes
• It is unclear if current leader Maulana Fazlullah, who comes from outside the tribal belt, is even in Pakistan, but he has a reputation for ruthlessness