TEHRAN - The death toll from an attack on a government building in Kabul has climbed to 43, according to local officials, as police and rescue workers engage in combing operations.

The deadly attack on a public welfare building in densely-populated area of Afghan capital took place on Monday when the gunmen held out for eight hours against security forces.

According to reports, a suicide bomber detonated his explosives-laden vehicle outside the building before gunmen stormed in, rampaging through the office complex.

U.N. Secretary-General's special representative for Afghanistan said in a statement that these attacks cause “untold human suffering to Afghan families”.

Tadamichi Yamamoto, who also serves as head of the UN Assistance Mission in Afghanistan, said the United Nations “unequivocally condemns them, as there is no justification whatsoever for such attacks.”

Afghan police evacuated more than 350 people during the encounter inside the government compound. Some employees managed to hide or jump out of windows, said a report by AFP. At least one policeman was killed, Interior Ministry spokesman Najib Danish.

This latest assault comes a few days after U.S. officials and Taliban held ‘secret parleys’ in UAE which was followed by President Trump announcing withdrawal of 7,000 troops from Afghanistan. U.S. officials had reportedly offered a role to Taliban representatives in the caretaker Afghan government.

The attack also came a day after Afghan President Ashraf Ghani appointed two anti-Taliban and anti-Pakistan figures to two top security posts, which evoked a mixed response in Afghanistan.