NAIROBI, Kenya (AP) — Ethiopian officials say they have arrested 76 suspects following unrest that erupted in the capital, Addis Ababa, during Eid al-Fitr prayers on Monday.

The unrest followed days of tension between the East African nation’s Christians and Muslims in various parts of the country after at least 21 Muslims were killed on April 26 in the northern city of Gondar.

Muslim representatives charged that extremist Christian groups carried out the killings and a dusk-to-dawn curfew has been imposed in Gondar, a tourist destination and one of Ethiopia’s largest cities with more than 300,000 people.

Six security officials were arrested for “negligence” over the killings, according to officials in the northwestern Amhara region.

Following the killings, a few Christian churches were burned in other parts of the country.

Amid these tensions, scores of thousands of Muslims gathered for Eid al-Fitr prayers on Monday in the capital city’s central Meskel Square where they planned to walk to the nearby stadium.

The procession became violent after tear gas was fired by police. Some windows were smashed, a nearby museum was attacked and rocks were thrown at police, according to local reports. Police arrested some of the protesters.

“A few individuals have caused an unrest that led to damages to property and injuries to security forces. Seventy-six suspects are now under custody,” Ethiopia's security task force said in a statement Tuesday without providing more details.

“We are investigating the causes of these clashes and will inform the public on our findings,” Markos Tadesse, a spokesman for the Addis Ababa police, said.

“It was all peaceful until one of the security personnel fired tear gas toward the crowd,” Najib Amin, an eyewitness said, adding that angry people then started throwing rocks in protest.

“It all came out of control after that. Several children were separated from their family members and some buildings around Meskel Square were hit by rocks,” he said.

The majority of Ethiopia's 115 million people are Ethiopian Orthodox Christians. About 34% of the population are Muslims.

Ethiopia’s religious groups have long coexisted peacefully, but ethnic and religious tensions have grown recently.

The ongoing civil war in Ethiopia's northern Tigray region has exacerbated ethnic tensions. It's estimated that conflict has caused the deaths of tens of thousands of people, especially of the Tigray ethnic group, according to international aid groups.