Four suicide bombers killed at least 25 people Monday in an area of Cameroon besieged by violence connected to the Islamist terror group Boko Haram, an official said.

Two bombers struck the central market in the northern town of Bodo, while two others targeted the town’s main entrance and exit points, an official told Reuters.

“There are around 25 deaths and several wounded,” the official added.

Officials who spoke to The Associated Press put the death toll at 28, with 65 people wounded.

There were no immediate claims of responsibility, although Boko Haram has stepped up attacks outside Nigeria over the past year, including targets in Cameroon, Chad and Niger, Reuters reports. The terror group claimed it kidnapped more than 200 schoolgirls in 2014, forcing many of them into sex slavery.

"We have information the four bombers came from Nigeria. We are investigating where they spent the night before attacking the market," the region's Governor Midjiyawa Bakari told The Associated Press.

A Cameroon troop commander, Gen. Jacob Kodji, confirmed the attack and said Boko Haram are suspected. He said some accomplices may still be in hiding.

"We have deployed soldiers to the area to assist the local defense group because we are informed a few fighters may have escorted them (the bombers) to Cameroon from Nigeria," he said

Cameroonian troops are part of an 8,700-strong regional force set up to defeat the terror group, which aims to create a separate state in northeastern Nigeria.

Bodo has been targeted in the past, most recently in December, when two female suicide bombers blew themselves up at the town’s entrance. There were no injuries in that incident.

Suicide bombers are suspected to be crossing the border from Nigeria to stage their attacks, killing dozens in the region in the last month, officials said. On Jan. 18, a 14-year-old suicide bomber attacked a mosque in the region, killing four, in the fifth attack on a mosque in Cameroon in less than a month.

Boko Haram's six-year insurgency has killed about 20,000 people and displaced 2.3 million, according to Amnesty International and the United Nations.

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The Associated Press contributed to this report.