Heavily armed Boko Haram Islamists kidnapped more than 100 girls from a school in north-east Nigeria on Monday night.

The mass abduction in Borno state came just hours after a bomb blast ripped through a crowded bus station on the outskirts of the capital Abuja, killing 75 people.

Gunmen stormed the Government Girls Secondary School after sundown, torching several buildings before opening fire on soldiers and police who had been guarding the school.

The girls were then forced onto lorries and driven away by the attackers, witnesses said.

Some of the schoolgirls escaped their kidnappers by jumping off a lorry in the middle of the night before running back to Chibok.

One of those who escaped said their opportunity to flee came when some of the gunmen became distracted after one of the vehicles in the convoy broke down.

Boko Haram is blamed for killing thousands of people across north and central Nigeria since 2009 in an uprising aimed at creating a strict Islamist state in the north.

The group has carried out scores of school attacks, spraying gunfire on students in their sleep and bombing educational buildings across the north.

Much of Boko Haram's recent violence has been concentrated in the north-east, where more than 1,500 people have been killed this year.

The military, which launched a massive offensive in the region last year, had claimed it has confined the Islamists in the remote region, a claim discredited by the bombing in the capital.