MAIDUGURI (Reuters) - A bomb hidden in a pile of scrap metal beside a busy road has killed two people and injured 33 others in Maiduguri, northeast Nigeria, military and hospital sources said on Wednesday.

The explosion, at around 1630 GMT, struck around 600 metres from army barracks and it follows a spate of bombings in the city by militant Islamist group Boko Haram that has killed around 80 people in the last few days.

"Thirty-three people that sustained various degree of injuries were brought to the hospital from the scene," a source at a local hospital told Reuters, adding that two dead people were evacuated.

Boko Haram has waged a six-year insurgency in the northeast of Africa's biggest economy and top oil exporter in a bid to establish an Islamic caliphate.

At the start of the year it controlled a swathe of territory around the size of Belgium, but the military says the group has been pushed back to the Sambisa forest in recent weeks - which Boko Haram denied in a video aired on social media on Tuesday.

New President Muhammadu Buhari, who visited his counterpart in Niger to discuss the group, has vowed to defeat the militant Islamists.