There are “cowards” in the Nigerian army who are frustrating the fight against Islamist militant group Boko Haram, the country’s national security adviser Sambo Dasuki has told the BBC in an interview.

Speaking to the BBC’s Newsday programme, Mr Dasuki said despite the cowardice by some of the soldiers in fighting Boko Haram’s "real security threat", close to 50% of the country’s soldiers was now deployed to the north-east, which he said showed how seriously the situation was being taken.

Boko Haram, which has a membership of between 6,000 and 8,000 was formed in 2002. It has killed an estimated 10,000 innocent Nigerians and caused the displacement of about 1.5 million people.

It recently, on January 3, 2015, killed, according to local reports, close to 2,000 people at Baga.

Nigeria’s defence ministry has, however, estimated the number of people killed to be not more than 150.

The terrorist group sacked the entire town during the attack. Some survivors fled to neighbouring Chad.

Two weekends ago, at least 23 people were killed by three female suicide bombers, one reported to be 10 years old.

In April 2014, the group kidnapped more than 270 schoolgirls in a village called Chibok.

Though some of the girls escaped to freedom, a lot more of them are still in captivity.

Apart from Chibok, several schools have been burnt and students burnt alive in towns and areas in the northeastern part of Nigeria by the terrorist group which is averse to any form of Western education.

Meanwhile US Secretary of State John Kerry says he plans to visit Nigeria in a couple of days.

Mr Kerry made the announcement in a speech discussing how to tackle violent extremism at the Davos economic conference.

Since the Nigerian government declared a state of emergency 20 months ago in three north-eastern states to deal with the insurgency, Boko Haram has strengthened and now controls several towns, where it has declared a caliphate.