(Reuters) - Boko Haram attacked a town in northern Cameroon on Monday, killing at least one person, an army source said, less than a week after the group issued threats against the Central African country.

The Nigerian group's insurgency, which is thought to have killed more than 10,000 people last year, has intensified in recent months and is posing a growing threat to neighbors Cameroon, Niger and Chad.

"They attacked our military base at Kolofata on Monday morning, killing one of our soldiers and wounding many others," said a source in the Cameroonian special forces who requested anonymity. Local paper L'Oeil du Sahel also reported the morning attack, saying the Islamic group had since been pushed back from the town.

Last week, a man purporting to be the leader of the Nigerian militant sect, Abubakar Shekau, threatened to intensify violence in Cameroon unless it scraps its constitution and embraces Islam.

Cameroon's President Biya, who was addressed in the video, has stepped up security in the far north in recent months but cross-border raids from Boko Haram's stronghold in Nigeria still occur.

He has appealed for international military help to fight Boko Haram. Chad also called for international aid last week after 2,000 refugees fled Boko Haram attacks and crossed the border from Nigeria into Chad.

(Reporting by Tansa Musa; Writing by Emma Farge; Editing by Giles Elgood)