Nigerian officials have warned that IS-aligned jihadists are training criminal gangs engaged in mass kidnappings in the country’s northwest, in a sign of deepening cooperation between armed factions.

The development could complicate threats facing Nigeria’s security forces who are mired in a 12-year conflict with Islamist militants in northeast Borno while battling criminals across northwestern states.

In a July 23 memo sent to his officers and seen by AFP, the Nigeria Immigration chief Muhammad Babandede warned of mass “movement of bandits from Zamfara in northwest to Borno for intensive Boko Haram training.”

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Nigerian officials use Boko Haram as a general term for all jihadist groups and heavily armed criminal gangs are often referred to locally as bandits.

“In view of this information,… you should intensify monitoring and surveillance around your area of jurisdiction with the view to gathering information,” the memo said.

Since the conflict began in 2009, several factions emerged within Nigeria’s Boko Haram jihadist group, with the Islamic State West Africa Province (ISWAP) now the dominant force after breaking away in 2016.

Since May, ISWAP has consolidated control in the northeast and security sources say militants forged a closer alliance with gangs in the northwest following the death of Boko Haram’s leader Abubakar Shekau in clashes with ISWAP fighters.

Northwest Nigeria has been long been terrorised by criminal gangs who raid villages, steal cattle, kidnap residents and burn homes after looting supplies.