“This attack shows complete contempt for human life, as well as the international law designed to protect diplomats,” said Tadamichi Yamamoto, the Secretary-General's Special Representative for Afghanistan.

The attack, which occurred in a residential area of central Kabul, lasted around five hours.

Several armed men killed two Afghan civilian employees inside the embassy and injured a police officer before being killed by Afghan security forces.

“I commend the Afghan security forces for their swift action that saved many lives,” said Yamamoto, who heads the UN Assistance Mission in Afghanistan, or UNAMA.

He noted that the attack is yet another which “appears to have targeted the international community but in which Afghan civilians bore the brunt of the violence.”

Diplomatic missions are civilian objects protected under international humanitarian law, and attacks directed at them are serious violations that may amount to war crimes.

The Islamic State in the Khorasan Province has claimed responsibility.