KABUL - A suicide bomber detonated explosives at a Lebanese restaurant frequented by foreigners in central Kabul late Friday, while two other bombers managed to get inside the restaurant and opened firing at the guests, killing 21 including 13 foreigners, according to officials.

Two others, including the chef of the restaurant, Taverna, has been wounded.

The victims include the Afghanistan head of IMF, Wabel Abdallah, and four UN employees. A British national is also reportedly killed in the attack.

The first explosion happened at 19:30 in the diplomatic district of Wazir Akbar Khan. Security forces reached the area and engaged in a two hour gunfire with the two gunmen who were resisting inside the building, said Kabul police chief Gen Zahir Zahir.

The restaurant is with high security and the reputation for serving foreign diplomats and aid workers. It is known to draw crowds on Friday nights.

The UN Secretary General Ban Ki-moon condemned the attack, calling it a "horrific attack".

"Such targeted attacks against civilians are completely unacceptable and are in flagrant breach of international humanitarian law. They must stop immediately," Mr Ban was quoted as saying.

The Taliban's spokesman Zabihullah Mujahid claimed responsibility for the attack, which he said was targeting foreign officials.

There have been a number of high-profile Taliban attacks in the capital since the start of 2014, after the country saw one of the bloodiest fighting seasons of the 13-year war last year.

The United Nations has attributed over 70 percent of all civilian casualties in Afghanistan to Taliban attacks. (Tolonews)