Gunmen have attacked a police station with explosives and automatic weapons in Kano, Nigeria's second most populated city.
A senior police officer said on Monday that the police station in Kano's Sharada neighbourhood had been burned down by attackers armed with explosives, who also shot one officer in the leg.
"The gunmen came from different directions to attack the Sharada industrial estate police station with bombs and gun shot some minutes after 6pm," Kano police spokesman Magaji Musa Majia'a told the Reuters news agency by telephone.
"One policeman was shot on the leg and he is receiving treatment in hospital.
"Our men at the station engaged them in a gun battle and as I speak to you now our men has taken over the place and are mopping up the area."
Boko Haram suspected
The gunmen were suspected of belong to the radical Islamist group Boko Haram. The group has claimed to have carried out a series of recent attacks in Africa's most populous nation, including co-ordinated gun and bomb assaults on January 20 in Kano that killed at least 185.
"I had just arrived home in time for the curfew when I heard an explosion coming from around the police station. Shortly, gunshots followed. From what I heard it sounded like a shootout," said Bala Salisu, 46, a witness from Kano's Sharada district.
A pharmacy in a market area in the remote northeastern city of Maiduguri, Boko Haram's heartland, was also blown up, witnesses said.
Al Jazeera's Yvonne Ndege, reporting from the Nigerian capital, Abuja, said residents feared the attack would be on the scale of the January blasts.
"Thankfully, we've been able to establish that it doesn't look like it is anywhere near the scale of what we saw back then," she said.
"But naturally, this attack on this police station has left people in Kano deeply worried that Boko Haram still has a foothold in the town and perhaps they are even planning more attacks."
Boko Haram is waging a low level campaign against the government and says it wants to impose Islamic law across the country of 160 million people split evenly between Muslims and Christians.
Nigerian secret service sources said they arrested Abu Qaqa, the purported spokesman for the group, on Wednesday although a man claiming to be him telephoned journalists from Maiduguri to deny it.
In a phone conference with journalists in the northeastern city of Maiduguri on Thursday, Boko Haram said that Abu Dardaa, the group's head of "public enlightenment", was arrested and not spokesman Abul Qaqa.