Nigerian army says kills 17 Islamist insurgents

Several military crackdowns and a state of emergency have failed to stop a rising tide of violence in northern Nigeria. A spate of bomb attacks on churches in the city of Kaduna last week triggered wider sectarian violence.

Most of the attacks have been blamed on Islamist sect Boko Haram which began an uprising against the government of President Goodluck Jonathan in 2009.

Police Commissioner Ibrahim Idris said 30 militants had used explosives and guns to attack Kano's Dala police division.

"The policemen gallantly repelled the attack ... During the gun duel in Dala Division, 10 of the extremists were killed," he said, adding that motor vehicles and explosives belonging to the militants had been recovered.

One policeman was killed and another was wounded, he said.

Five insurgents were killed in a separate gun battle at Jakara police barracks, he added, while two more had been killed after their group attacked a mobile police unit. Three suspected insurgents had also been captured, he said.

Separately, Muhammad Abubakar, police commissioner for Kaduna state, which erupted into violence that killed more than 90 people last week after three churches were bombed, said 14 suspected sect members had been arrested.

The arrests were made on Tuesday, he said, but he gave no further details. A total of 147 people suspected of involvement in reprisal attacks have been detained since last week, he added.

Boko Haram, which wants to carve out an Islamic state in Nigeria - whose inhabitants are split 50-50 among Muslims and Christians - was not available for comment and there was no way to independently verify the police report.

Gun and bomb attacks blamed on Boko Haram have killed hundreds since 2009.

The killing and capture of some top Islamists may have weakened the sect in the past few months, though they have shown surprising resilience and an ability to spread their insurgency across much of the north.

President Jonathan said on Sunday he had sacked his defence minister and national security adviser because the government needed new anti-terrorism tactics - a sign he may be realising how serious the security threat to Africa's top energy producer is.

Boko Haram has rapidly overtaken militants in the oil-producing southern Niger Delta to become his number one headache, and shows no sign of winding down its attacks.

The authorities have captured hundreds of suspected militants, but haven't always managed to keep them locked up. Boko Haram fighters stormed a prison in their northeastern heartland on Sunday, freeing 40 inmates.

(Reporting by Augustine Madu; Additional reporting by Garba Mohammed in Kaduna; Writing by Tim Cocks; Editing by Michael Roddy)