Local residents talking to correspondents, so maybe not 100% accurate and I've checked other on-line news reports:
The attacks by suspected members of the radical Boko Haram sect, which also seriously injured two other policemen, happened in the town of Azare and lasted four hours, they said.

The attackers armed with heavy machine guns, threw explosives and fired heavy machine guns into a regional police headquarters and an adjoining police station in the town, setting fire to the buildings, residents said.
Link:http://www.telegraph.co.uk/news/worl...lls-three.html

Wikipedia for a map and background:http://en.wikipedia.org/wiki/Azare