(CNN) -- Gunmen overran a police headquarters and a government building in northeastern Nigeria early Thursday, killing four people, including two civilians, officials said.
About 100 gunmen attacked the divisional police headquarters and the local government secretariat in the town of Song, in Adamawa state, police spokesman Mohammed Ibrahim said.
The attackers set both buildings on fire, he said.
The fire spread to a house near the police station, where a 64-year-old woman and her 4-year-old granddaughter died. A soldier and a police official also were killed.
Attacks by the Islamist militant group Boko Haram have been reported in the state before, but the group did not immediately claim responsibility for the attack.
"I'm appealing to members of the public to help law enforcement by providing us with useful information," Ibrahim said. "I want civilians to know that we are their friends and here to protect them."
Last week, gunmen with suspected ties to Boko Haram killed two people and wounded another in an attack in Maiha, also in Adamawa state. The attackers freed 35 inmates from the Maiha prison and set government buildings on fire.
On Wednesday, Nigerian troops clashed with gunmen who attacked in northern Borno state, military spokesman Lt. Col. Sagir Musa said. One soldier and one police officer were killed, in addition to five gunmen who died in the fighting.