YOLA, NIGERIA (Reuters, AFP) - Suspected Boko Haram militants kidnapped at least 25 girls in an attack on a remote town in northeastern Nigeria, witnesses to the attack said, despite talks aimed at freeing more than 200 other female hostages the militants seized in April.

Mr John Kwaghe, who witnessed the attack and lost three daughters to the abductors, and Dorathy Tizhe, who lost two, said the attackers came late in the night, forcing all the women to go with them, then later releasing the older ones.

A deadly bombing in northern Nigeria and new details about kidnappings at the weekend blamed cast further doubt Thursday on the government's claim that the Islamists have agreed to a truce.

As reports emerged that extremists seized dozens more women and girls from the remote northeast - leaving a few dollars behind as a so-called 'bride price' - fresh violence rocked the town of Azare in Bauchi state.

A police spokesman for the state, Mr Mohammed Haruna, said a bomb blast at a bus station in Azare killed five people, with their bodies "burnt beyond recognition," and injured 12 others. No-one claimed responsibility, but Bauchi has been attacked repeatedly throughout Boko Haram's brutal five-year uprising, which has left more than 10,000 people dead.

Azare resident Musa Babale said the explosion on Wednesday "shook buildings" and sent locals rushing for shelter. "The whole place was a mess," he told AFP after visiting the site.

Several witnesses said they believed the bomb had been planted in a parked car, but police did not give details on the nature of the device. Bus station bombings have become something of a hallmark for the insurgent group after twin attacks at a terminal on the outskirts of the capital Abuja earlier this year killed nearly 100 people.

The station in Azare, a town roughly 200 kilometres (125 miles) from the state capital Bauchi city, is a widely used transit point for travellers coming from Nigeria's embattled northeast, which has been under a state of emergency since May last year.