Eight people were killed as a wave of suicide bombers attacked Britain's cultural centre in Kabul on Friday, a public holiday marking Afghanistan's independence from London in 1919.

Two blasts struck the British Council offices after three or four Taliban suicide bombers infiltrated the compound, prompting gunbattles which started at around 5:45am (0115 GMT) and continued to rage for more than eight hours.

Four further explosions were heard during the course of the attack, which underscored perilous security in the heart of the capital with US-led NATO combat troops starting to withdraw from Afghanistan before a 2014 deadline.

The British Council is an official organisation part-funded by the British government that promotes cultural relations in offices around the world.

Thick black smoke spewed out of the Council close to the burning wreckage of a car that had rammed into the wall of the compound and exploded. Ambulances and the emergency services shuttled back and forth rescuing injured people.

Afghan interior ministry spokesman Siddiq Siddiqui reported up to two foreign casualties during the attack, without specifying their nationality.

An official speaking on condition of anonymity said the dead included "two to three Nepalese", but British officials later announced that all Britons were safe and that there were injuries but no deaths among the Gurkhas.

British government offices in Kabul are often guarded by Nepalese ex-Gurkha soldiers now working for private security firms.

"I condemn this despicable attack on the British Council building in Kabul earlier today," Foreign Office Minister Alistair Burt said in London.

"I can confirm that all British nationals affected are now safe. It is due to the presence of mind of the staff involved and our good security measures that no British nationals were hurt."

The Kabul government said eight people, mostly police, were killed and 10 others injured, after three or four suicide bombers stormed the compound.

Shortly before 2:30pm, British ambassador to Kabul, William Patey, said all insurgents involved in an attack had been killed.

He added that some of those inside the compound had hidden in a safe room, including a South African who worked there and a British security guard.

An AFP team at the scene saw British, French and US forces scrambled to the site, with two large NATO armoured vehicles arriving as helicopters circled.

At one point, a helicopter landed close to the scene of the attack, possibly to evacuate the wounded, while Afghan security forces took up position on the roofs of buildings nearby, an AFP reporter said.

Witnesses told how they were jolted from their sleep by the sound of the first blast.

"It woke us up. The windows and glass were broken, the firing was going on, and my two daughters were slightly injured (by shattered glass)," said Amadullah, a shopkeeper living in the house next door to the British Council.

A spokesman for the US-led NATO force, Captain Justin Brockhoff, said the international military had sent a "limited number" of troops to the scene.

"We have a very small contribution to the Afghan-led response," he said. Afghan security forces are in overall control of security in Kabul.

Taliban spokesman Zabihullah Mujahid, contacted by AFP, claimed the militant group leading a 10-year insurgency in Afghanistan was responsible for the attack, which he said was to mark the nation's independence day.

He said the attackers' target was the British Council and a UN guest house. But a spokesman for the UN Assistance Mission in Afghanistan, Dan McNorton, denied any of its sites were involved.

"Today is our independence day from Britain. They recognised our independence 92 years ago. Today's attack was marking that day," Mujahid said.

"Now the British have invaded our country again and they will recognise our independence day again."

Britain is the second-largest provider of troops to the international military effort fighting the Taliban in Afghanistan after the United States, with around 9,500 forces mainly in the south.

The British Council says its work in Kabul is focused on providing support for Afghans wanting to learn English, "for which there is an overwhelming demand".

While Kabul is seen as more stable than some other parts of Afghanistan, it has been hit by a series of high-profile attacks.

In the most recent, 21 people were killed in June when the Taliban attacked the city's Intercontinental Hotel, popular with foreigners.