Three suicide bombers exploded at a checkpoint where scores of people were being searched for a bustling weekly market Friday in Nigeria's northeastern town of Madagali, witnesses said. The blasts killed two self-defense fighters who wanted to search them.

Their challenge likely saved many lives. In December, two women suicide bombers killed 57 people and wounded 177, including 120 children, at Madagali market. Last week, three girl suicide bombers were killed on the outskirts of the same town.

Residents blamed Boko Haram Islamic extremists for the attacks. Madagali is about 150 kilometers (90 miles) southeast of Maiduguri, the largest city in the northeast and birthplace of Boko Haram's insurgency.

"They blew up themselves after they were intercepted by local vigilantes stationed at the checkpoint at the entry to town," resident David Abawu said by telephone. "Two vigilantes lost their lives in the process."

Nigeria's military and civilian self-defense fighters who work with them have intercepted many suicide bombers in recent months, preventing much higher death tolls.

President Muhammadu Buhari last month declared that Boko Haram had been crushed, but it is unlikely there will be a swift end to the suicide bombings and attacks on remote villages and army outposts.

Boko Haram's seven-year uprising has killed more than 20,000 people, driven 2.6 million from their homes and created a massive humanitarian crisis that the U.N. says has 5.1 million people in Nigeria facing starvation.

AP