Boko Haram Islamist militants have attacked the northern Nigerian town of Buni Yadi, which they lost to a Nigerian army offensive in March, military sources said.

A Reuters correspondent saw a detachment of troops with armoured personnel carriers and a fighter jet heading towards Buni Yadi in Yobe State on Friday morning. It was not clear if fighting was continuing in the area.

There was no information on casualties after the attack, which started at around 9 p.m. (2000 GMT) on Thursday, the sources said on Friday.

“Those boys (Boko Haram) came to Buni Yadi yesterday and attacked our people. They came in about nine Hilux (pick-up trucks) and opened fire ... Our people have mobilized for reinforcement,” one of the sources said.

Boko Haram has been trying to carve out a state adhering to strict sharia in the country’s northeast since 2009. Buni Yadi was one of the towns captured by the insurgent group in 2014 and then reclaimed in March by Nigeria’s army.

•Photo shows Boko Haram insurgents.