The center of Kabul city witnessed a complex attack by at least four gunmen on Saturday after months of relative calm in the Afghan capital amid accelerating efforts for the peace process.

The attack started with a suicide bombing outside the Ministry of Telecommunication and Information Technology in Kabul’s PD2 – which is located in the once-famous 18-story building built during the Soviet occupation in Afghanistan.

The attackers breached the heavily-fortified compound an hour after the first explosion and fought for five hours near and inside the first floor of the building.

The ministry is surrounded by other key government compounds – including the Ministry of Information and Culture and the Central Postal Service Organization.

Employees of all the surrounding government organizations were evacuated sharply after the attack started at around 11:40 Kabul time. At least 2,000 employees of the Ministry of Communication and Information Technology were either evacuated or were taken to the “safe rooms” as officials described it after the attack.

The center of the city, which connects main markets to other parts of Kabul, was paralyzed for the rest of the day after the attack happened.

Ministry of Interior in a statement later in the day said that at least seven people, including three security force members, were killed and six others were wounded in the attack.

The gunmen had police and military uniforms, said Sayed Mohammad Roshandil, Kabul’s Police Chief.

The incident left the employees of the Ministry of Communication in shock as some of them were “not able” to talk to TOLOnews after they were evacuated from the building, the TOLOnews reporter Tamim Hamid described.

According to the Ministry of Interior, The attack ended at around 5pm Kabul time.