Kandahar, Afghanistan: Taliban insurgents launched a major attack Sunday against a Nato base at an Afghan city airport with suicide car bombs, rocket-propelled grenades, mortars and small arms fire.

The Taliban claimed insurgents had entered the airport at Jalalabad, near the eastern border with Pakistan, but this was denied by NATO's International Security Assistance Force (ISAF).

"Insurgents including suicide bombers attacked the perimeter of the Jalalabad air base this morning," a spokesman told AFP.

"None of the attackers succeeded breaching the perimeter."

The airport complex has multiple layers of security, with the NATO base set well back from the first entrance, which an Afghan official said had been breached.

There were no early reports of ISAF casualties but one Afghan security force member was reportedly killed and another was wounded, he said.

An Afghan security official told AFP he had seen five dead men in Afghan army uniform, but it was unclear whether they were soldiers or Taliban attackers.

The Taliban said their militants had entered the airport, and an Afghan government official confirmed that clashes had taken place within the airport complex.

"First a fedayee (suicide bomber) mujahid... detonated a car bomb causing the enemy heavy casualties and losses and removed all the barriers," the Taliban said on their website.

"After the attack other fedayee mujahids entered the base... and started attacking the invading forces in the base."

A guard said that after the initial huge explosion the airport had come under fire from rocket-propelled grenades, mortars and small arms.

The hardline Taliban Islamists have waged an 11-year insurgency against the Afghan government, which is backed by 100,000 NATO troops, since being overthrown in a US-led invasion for harbouring Al-Qaeda leader Osama bin Laden.

The airport has come under attack on two previous occasions this year.

On February 27, six civilians, an Afghan soldier and two local guards were killed in a suicide car bomb attack on the military base at Jalalabad airport, but NATO troops escaped unhurt.

The airport also came under attack on April 15, when the Taliban launched their spring offensive with a series of commando-style assaults across Afghanistan.