Boko Haram leader Abubakar Shekau mocked his opponents at the weekend with a new video claiming to have married off over 200 kidnapped schoolgirls.

"If you knew the state your daughters are in today, it might lead some of you ... to die from grief," the extremist group's head told the girls' parents.

He said that they have all been converted to Islam and married off, dashing hopes for their freedom.

Mr Shekau denied that there is a ceasefire with the Nigerian government in operation and also threatened to kill an unidentified German hostage.

"Don't you know we are still holding your German hostage (who is) always crying. If we want, we will hack him or slaughter him or shoot him," he taunted the government of President Goodluck Jonathan.

An unnamed German development worker is believed to have been seized at gunpoint in Gombi in July as he drove to work.

The new video shows Mr Shekau flanked by masked and armed fighters standing in front of four military pickup trucks mounted with anti-aircraft guns.

Boko Haram has looted many weapons and vehicles including armoured cars from Nigeria's military, which has claimed several times to have killed Mr Shekau.

Nigeria's military chief Air Chief Marshal Alex Badeh announced on October 17 that Boko Haram had agreed to an immediate ceasefire to end a five-year insurgency in which thousands have died and hundreds of thousands have been driven from their homes in north-east Nigeria.

Government officials also said they expected the kidnapped schoolgirls to be released any day.