By Ibrahim Mshelizza
MAIDUGURI, Nigeria (Reuters) - An Islamic sect responsible for almost daily killings in remote northeastern Nigeria is thought to be behind a bombing Thursday that injured policemen and soldiers, police said.
The explosion followed an attack on a police station late on Wednesday by suspected members of Boko Haram, a group behind frequent attacks in the northeastern state of Borno, one of the poorest areas in Africa's most populous nation.
"Three policemen and two soldiers have been injured in an early morning bomb blast in Maiduguri ... four suspects have been arrested following Wednesday's attack," the Borno police commissioner, Mohammed Abubakar, told Reuters.
A spokesman for Nigeria's National Emergency Management Agency (NEMA) said there had been three bomb blasts in different locations around Maiduguri between Wednesday night and Thursday morning but the police said there was only one explosion.
NEMA said it was mobilising response workers to aid the injured but could not confirm if anyone had been killed.
The governor-elect of Borno state offered Boko Haram amnesty shortly after winning April elections to try to end months of attacks on symbols of authority including politicians, policemen and the army. But the sect rejected the offer.
The army in the state capital Maiduguri heightened security checks and arrested suspects after four soldiers were killed on Sunday in clashes with gunmen. A Borno police spokesman said Boko Haram had killed 50 officers since its uprising.
Sect members launched an uprising in 2009, attacking government buildings and triggering days of gun battles with the security forces in which up to 800 people were killed.
Its attacks became increasingly political in the run-up to last month's presidential, parliamentary and state governorship elections, but there has been no let-up in the violence since then.
(Writing by Joe Brock; editing by Tim Pearce)