While there was no immediate claim of responsibility, suspicion fell on the Islamic State West Africa Province, also known as ISWAP.
Shortly after the explosions rattled the city, Buhari arrived to meet with the nation’s security heads and government officials in Borno.
Although Nigerian troops in the northeast have scored some gains against the rebels since the death of ISWAP leader Abu Musab al-Barnawi earlier this year, the group continues to infiltrate local communities and target security forces in ambushes.
In a statement Tuesday, the group claimed killing at least 20 members of a pro-Nigerian army militia in the town of Kilangar in Borno state.