Boko Haram Nigeria North
Policemen stand near damaged vehicles in Sabon Gari, Kano, after a Boko Haram car bomb attack killed five earlier this year.Reuters

A suspected suicide bomb attack by the Nigerian Islamist militant group Boko Haram has left at least nine dead after striking a bank in the country's northeast.

The device exploded at a First Bank of Nigeria branch in Azare in Bauchi state, a source told Reuters.

"After the smoke had dissipated, we saw a number of bodies - I saw with my own eyes at least nine bodies without heads or limbs," an eyewitness told BBC.

No group has yet claimed responsibility for the attack but Boko Haram have carried out numerous attacks in the state.

Last month, the group bombed a bus station in Azare, killing at least five people and wounding 12.

Nigerian media outlets reported that the victims of the attack were lining up to use the ATM machine at the bank when the bomb detonated.

It is believed that many residents of the neighbouring states of Borno and Yobe, which have been under a state of emergency since 2013, travel into Bauchi state to retrieve money from banks as they have no banks or working cash machines in their areas.

Last month, the Nigerian government declared that a ceasefire had been agreed with the terror group but the militants released a video denying the Nigerian regime's claims.

According to Human Rights Watch, the militants have killed at least 2,053 people since the beginning of 2014, but researchers at the John Hopkins University School of International Studies estimate that 7,000 people have been killed in the 12 months between July 2013 and June this year.