A police official in northern Nigeria says security forces have chased away foreign religious radicals outside the main city of Kano, restoring order ahead of Saturday's presidential election. The clashes between security forces and suspected Islamic militants follow the killing of an influential Muslim cleric last week. VOA's Nico Colombant reports from Kano.

Police commissioner Atiku Kafur tells VOA army reinforcements helped chase away the several hundred insurgents who were lightly armed, spoke only Arabic and had holed up in a suburb of Kano. "The military started shelling their strongholds, they succeeded in killing some of them, and arresting some of them; so as I speak now, I can say the area is quiet. They have been seen running away," he said.

On Tuesday, police reported the assailants killed 12 policemen and one civilian.

Kafur, who took the job of police commissioner only several weeks ago, says he was completely surprised by the attacks. "It is quite a surprise, that is why we are even getting to find out when did they come, have they been here for a long time, or have they just arrived? That is what we are investigating right now," he said.

Kafur says he has strong evidence there is a link between the attack and the murder of Sheik Jaafar Adam, an influential Sunni cleric, last week. He says one of his top priorities is to find the killers. "We are spreading our tentacles to various angles, including political, legal, whatever. We will not leave any stone unturned. We will make sure that we get those who killed that Sheikh," he said.

Kano is one of 12 predominantly Muslim states in the north of Nigeria. The south is mostly Christian and animist.

Waddah Mohammed, a Kano businessman, says the local residents blame outsiders for trying to disrupt the region ahead of the presidential ballot. "Whenever you ask, the people did not associate with them, with any of the Islamic sects in Kano. And they did not call anybody's name here in Kano. And they say they have only come to face the law enforcement agents so this is what confuses people," he said.

To cut down on violence, police have imposed a nighttime curfew.

In a quiet part of Kano, one motorbike taxi driver, waiting at a repair shop, says he is grateful for the curfew and the extra security. "If people are coming out, they will be fighting with police or some other people, and that this is why they are doing anything around. From 5:30, they are going back to their house and nothing is happening with (because of) the curfew," he said.

Opposition parties have called for protests and a boycott of Saturday's presidential elections unless last week's gubernatorial ballot that they claim was riddled with fraud is annulled.

But the election commission says the opposition leaders should address their grievances in the courts, and says the presidential elections will take place as scheduled.