"So far, we have received four dead and 27 injured including police and civilians," a doctor in Herat hospital Barakatullah Mohammadi said.

Meantime, gun fight continues between attackers and security forces, police said.

Four blasts have shocked Herat city since beginning attack on security forces at around noon time.

NATO helicopters are flying over the area to control the situation.

A group of attackers with some of them suicide bombers occupied a building next to the NATO-led Provincial Reconstruction Team (PRT) at around 11:50 a.m. local time and begun targeting the compound.

The attackers first detonated a car bomb next to the PRT office and then stormed the building, according to police.

Immediately after the attacks, Afghan police and army personnel have rushed to the area.