The number of people injured in a powerful explosion Sunday morning in Afghanistan's western city of Herat has risen to 36, head of Herat hospital said.

"We have received 36 wounded people in our hospital this morning, 24 of them in critical conditions," Dr. Syed Mohammad Omar Samim told Xinhua.

Another five including a child were killed in the blast, the doctor added.

The incident coincided with the launching of the UN-backed Disarmament, Demobilization, Reintegration (DDR) program in the morning rush hour at a busy center in the city.

Under the program, 60 percent of around 100,000 militiamen loyal to different commanders will be disarmed before the presidential elections rescheduled for October 9.

Herat Governor Ismael Khan visited the explosion site and the injured ones in hospital. He ordered authorities to shift the critically injured people to neighboring country Iran for treatment.

In the meantime, Defense Ministry's spokesman Zahir Azimi termed the blast as an act of "Afghanistan's enemies", a term usually used for the Taliban.

"Afghanistan's enemies are behind the coward incident to undermine peace and security in the country, but their desperate efforts are doomed to fail," Azimi told Xinhua.

The spokesman of Herat governor also condemned the explosion as an act of enemies, saying: "The only motivation behind the barbaric act is to destroy peaceful life of common people."