Updated

A police official says Nigerian soldiers have foiled an attack by three female suicide bombers targeting the largest city in the country's northeast region.

Victor Isuku, deputy superintendent of police in Borno state, said the assailants were spotted heading toward Maiduguri early Friday morning with bombs strapped to their bodies. He said soldiers shot at them and that two of their bombs exploded, killing all three.

He said a police bomb disposal unit then detonated the unexploded bomb.

Boko Haram frequently uses female suicide bombers. Its uprising has killed more than 20,000 people over seven years.

The Nigeria-based militant group has recently stepped up attacks after a months-long lull. On Nov. 1, a car bomb targeted a military checkpoint on a road leading to Maiduguri, killing nine people.