The militant group Mend, Movement for the Emancipation of the Niger Delta, claimed responsibility for an attack in South Nigeria on Friday which killed 12 police officers.
The announcement came in an email, and went on to say that the group would relaunch attacks after its leader, Henry Okah, was jailed in South Africa for 24 years for the 2010 bomb attacks in Abuja.
Thousands of former militants are reportedly not receiving the monthly allowance that was promised to them as part of the 2009 amnesty agreement, reports the BBC.
The police commissioner Kingsley Omire said:
"The officers became soft target for some hoodlums, who we have confirmed were part of a militant group that was supposed to be enjoying an amnesty."
