At least 18 people, including 14 foreigners, were killed during a 13-hour siege after Taliban gunmen dressed in army uniforms stormed the Kabul Intercontinental Hotel.

Key points: The more than 150 people who were rescued or managed to escape included 41 foreigners, Interior Ministry says

The more than 150 people who were rescued or managed to escape included 41 foreigners, Interior Ministry says The Taliban claimed responsibility for the attack

The Taliban claimed responsibility for the attack Investigators are looking into how the assailants gained access to the hotel

Security forces said they had killed the last of six Taliban militants to end the Saturday night (local time) siege inside the luxury, hilltop hotel

Some of the 150 guests fled the gun battle and fire sparked by the assault by shimmying down bedsheets from the upper floors.

Guests said they had no choice but to "burn or escape" as gunmen roamed the hallways targeting foreigners and Afghan Officials.

A man tries to escape from a balcony at Kabul's Intercontinental Hotel. ( Reuters: Omar Sobhani )

The more than 150 people who were rescued or managed to escape included 41 foreigners, Interior Ministry spokesman Najib Danish said.

Of those, 10 people were injured, including six security forces, he said.

Eleven of the 14 foreigners killed were employees of KamAir, a private Afghan airline, Danish said. KamAir put out a statement saying some of its flights were disrupted because of the attack.

Six of those killed were Ukrainians, said Ukrainian Foreign Minister Pavlo Klimkin, who added that his office was working with Afghan law enforcement agencies "to clarify the circumstances of this terrorist act".

A citizen from Kazakhstan also was among the dead at the hotel, according to Anuar Zhainakov, a spokesman for the Kazakh Foreign Ministry.

Sorry, this video has expired Kabul's Intercontinental Hotel has come under attack for a second time in seven years. )Photo: AP/Massoud Hossaini)

Afghan security officials confirmed that 34 provincial officials were at the hotel for a conference organized by the Telecommunication Ministry.

Afghan officials said that also among the dead was a telecommunications official from Farah province in western Afghanistan; Waheed Poyan, the newly appointed consul general to Karachi, Pakistan; and Ahmad Farzan, an employee of the High Peace Council, a commission created to facilitate peace talks between the Afghan Government and the Taliban and other opposition groups.

The Taliban claimed responsibility for the attack at the heavily guarded hotel that is popular among foreigners and Afghan officials.

Taliban spokesman Zabihullah Mujahid said the insurgents initially planned to strike the hotel Thursday night (local time) but postponed it because a wedding was underway there and they wanted to avoid civilian casualties.

The attack unfolded almost six years after Taliban insurgents launched a similar assault on the property.

Insurgents gained access through kitchen: early finding

Mumtaz Ahmad, a provincial telecommunication employee for Helmand province, said he was walking from his room to the reception for his group on Saturday night.

"When the elevator door opened, I saw two armed suicide bombers. People were escaping and the attackers were firing at them," he said.

Fire broke out in the six-story hotel as the fighting raged, filling some guest rooms with smoke. Explosions could be heard throughout the standoff.

Afghan security personnel stand guard as smoke rises from the Intercontinental Hotel. ( AP: Rahmat Gul )

Live TV video showed people trying to escape through windows and from the upper stories as thick, black smoke poured from the building.

The Interior Ministry said it was investigating how the attackers managed to enter the building.

It said a private company had taken over security about three weeks ago at the hotel, which is not part of the Intercontinental chain.

During a news conference, Mr Danish said an initial investigation showed that six insurgents entered the hotel from the northern side and stormed its kitchen.

A person or persons inside the hotel might have helped the attackers gain entrance, Mr Danish said.

Two of the attackers were killed by special forces on the 6th floor of the hotel.

Staff and residents fled the building amid bursts of gunfire. ( Reuters: Mohammad Ismail )

Neighbouring Pakistan condemned the "brutal terrorist attack" and called for greater cooperation against militants.

Afghanistan and Pakistan routinely accuse each other of failing to combat extremists on their long and porous border.

Afghan forces have struggled to fight the Taliban since the US and NATO formally concluded their combat mission at the end of 2014.

They have also had to contend with a growing Islamic State affiliate that has carried out a number of big attacks in recent years.

AP