ABUJA, Nigeria (AP) — Islamic extremists killed nine people and injured four in Borno state in northeastern Nigeria, authorities said Sunday.

The attack was carried out by Boko Haram militants on the Malam Fatori community, Babagana Zulum, the state governor, said. He did not say when the attack happened.

The community, very close to the border of Chad, is about 270 kilometers (167 miles) from Maiduguri, Borno’s capital city.

The governor, represented by Sugun Mai Mele, the commissioner for local governments, visited the community and warned residents against collaborating with Boko Haram militants.

“Anyone found collaborating with the insurgents to bring harm or attack to the people of Malam Fatori will be cursed,” he said, adding that there are measures being put in place to fortify the town against future attacks.

A resurgence of Boko Haram attacks has been shaking Nigeria’s northeast in recent months, as Islamic extremists have repeatedly overrun military outposts, mined roads with bombs and raided civilian communities, raising fears of a possible return to peak Boko Haram-era insecurity despite the military’s claims of successes.

Last month, a suicide bomber suspected to be female killed at least 10 people and injured several others in an explosion in a restaurant in the Konduga area of Borno, as the state struggles to curb attacks by the extremists.

Boko Haram, Nigeria’s homegrown jihadis, took up arms in 2009 to fight Western education and impose their radical version of Islamic law. The conflict also has spilled into Nigeria’s northern neighbors.

Some 35,000 civilians have been killed and more than 2 million displaced in Nigeria's northeastern region, according to the U.N.

Apart from the insurgency in the northeast, Africa’s most populous country is also facing serious security challenges in the north-central and northwest regions, where hundreds have been killed and injured in recent months.