Suspected militant Islamists have killed at least 29 people in an attack on a town in north-eastern Nigeria's Borno state, a lawmaker has said.

Government troops fled when the militants raided Mafa town on Sunday night, Ahmad Zannah added.

The attack brings to about 150 the number of people killed in Borno since Friday in attacks by the militants and the military, reports say.

The Islamist group Boko Haram is waging an insurgency in Nigeria.

President Goodluck Jonathan declared a state of emergency in Borno and two other states in May, giving the military extra powers to curb the four-year insurgency.

However, Boko Haram has stepped up its violent campaign, with hardly a day going by without reports of a deadly attack by militants, says BBC Nigeria correspondent Will Ross.

Thousand of people have been killed in the conflict and hundreds of thousands have fled their homes.

'Air raid'

Mr Zannah, a senator from Borno state, told BBC Focus on Africa that Boko Haram had warned about a week earlier that it planned to attack Mafa.

Schools were shut and most residents fled to Maiduguri city, about 45km (28 miles) away, he said.

Military reinforcements were sent to Mafa, but soldiers still lacked the firepower or numerical strength to confront the militants, Mr Zannah added.

"When the attack took place, all of them ran away, along with the villagers. There was no resistance," he said.

Two policemen were killed by a bomb on Monday morning and fourteen soldiers were missing, Mr Zannah said.

On Saturday night, suspected Boko Haram fighters reportedly destroyed the entire village of Mainok, about 50km west of Maiduguri.

The militants attacked the village with assault rifles, rocket-propelled grenades and explosives, killing 47 people, residents said.

Earlier on Saturday, two bombs killed about 50 people in a densely populated area of Maiduguri - a city which Boko Haram has often targeted.

Borno state senator Ali Ndume told BBC Hausa that about 20 people, many of them elderly, were killed when the army launched an air raid on Daglun village on Friday night.

However, the defence ministry denied the allegation.

"The reports are believed to be part of the design by those bent on discrediting the counter-terrorist mission," its spokesman Chris Olukoladehe is quoted by the AFP news agency as saying.

He said government forces had killed a number of Boko Haram fighters in an operation on Sunday evening, including those believed to have killed at least 29 people in an attack on a rural boarding school in Yobe state more than a week ago.

Boko Haram members suspected to have been involved in the bombings in Maiduguri have also been arrested, Mr Olukoladehe said, AFP reports.

Both the Nigerian army and Boko Haram have repeatedly been accused by rights groups of committing atrocities during the conflict in the region.