At least 100 people died and 130 were wounded in an attack on a popular marketplace in the town of Khan Beni Saad northeast of the capital city of Baghdad, with responsibility claimed by the terrorist Islamic State (IS) group, according to the latest report provided to EFE by a local security official.

Another 20 people have gone missing, but their bodies are believed to have disintegrated Friday in the explosion of a truck-bomb next to the market that was packed with shoppers at the time of the blast, the official said.

Besides the victims, 50 local shops were destroyed and 70 vehicles burned up by the powerful explosion, which opened a huge crater in the ground.

The IS claimed responsibility for the attack with a Twitter post that said it was carried out by an Iraqi suicide bomber who detonated a vehicle loaded with 3 tons of explosives.

The terrorist group claimed the operation killed 180 Shiite militiamen who had gathered near the local mosque, and said it also caused considerable destruction in the area.

A security official in Baghdad told EFE that most of the victims were in fact civilians doing their shopping for the festivities celebrating the end of the holy month of Ramadan.

Local authorities have formed a commission to investigate the attack and determine how a truck-bomb could get to that place in spite of the security measures in place for the end of Ramadan and the religious festival of Eid al-Fitr.

For his part, Gov. Muthana al-Tamimi of Diyala province, where the attack took place, decreed three days of mourning Thursday night and suspended the Eid al-Fitr celebrations.

During these festive days, families tend to gather in city squares, parks and marketplaces to buy candy and gifts, and for that reason security had been strengthened in public places.

Khan Beni Saad is located 50 kilometers (30 miles) south of the town of Baqubah, the capital of Diyala province, and the majority of its inhabitants are Shiites, a branch of Islam that tends to be targeted by IS attacks.

This was one of the deadliest attacks since the jihadist group conquered wide areas of the country in June 2014 and proclaimed the areas under its control in Iraq and Syria a caliphate.