Nnmadi Kanu
Pro-Biafran leader Nnamdi Kanu arrives in court in Abuja, capital of Nigeria, on 25 January 2016Ipob

Ex militants backing the ongoing struggle for the independence of the disputed Biafran territories have allegedly hijacked a ship and are threatening to kill the crew if the Nigerian government does not release pro-Biafran leader Nnamdi Kanu, AP quoted the Nigerian military as saying.

The hijacking reportedly happened in the Bakassi Peninsula, in the Atlantic Gulf of Guinea, according to Nigerian media. A militant spokesman, known only as General Ben, said there was a possibility the hijackers would not wait for a 31-day ultimatum given to the government before blowing up the vessel.

"We cannot wait until the end of the 31 days to tell the federal government that we are serious. The vessel and the crew are in our custody," Ben said. "Any noise, any delay from government, we will blow up everything. We will blow [up] the vessel and everybody in the vessel will go down," he continued.

Although the identity of the ex-militants is not clear yet, Uchenna Madu, one of the leaders of the Movement for the Actualization of a Sovereign State of Biafra (massob), told AP: "Some Niger Delta militants have shown interest in working with us." In a previous report by IBTimes UK, intelligence consultant David Otto warned some pro-Biafrans might be joining forces with militants from the Niger Delta, southern Nigeria.

IBTimes UK has contacted the Nigerian government and military for a comment, but had not received a response at the time of publishing. A member of the Indigenous People of Biafra (Ipob), who spoke on conditions of anonymity, confirmed the vessel had been hijacked.

Kanu, leader of Ipob and director of Radio Biafra, was arrested by the State Security Service in Lagos in October 2015 on conspiracy and terrorism charges that were later dropped. A day after the Abuja High Court ruled he should be released, officials pressed new treasonable felonycharges against him, while President Muhammadu Buhari said Kanu would not be granted bail due to the "atrocities" allegedly committed.

In January, a federal court in Abuja denied bail to Kanu arguing that he might leave the country as he holds both a British and a Nigerian passport.

Pro-Biafrans call for the independence of the territories forcibly annexed to Nigeria during the British colonisation, which ended in 1960.

Nigeria up close: Check out our Flipboard magazine