The Defence Headquarters says 13 Boko Haram terrorists alongside six women and 17 children from Kodila village have surrendered to troops of 151 Task Force Battalion at Banki Junction in Bama Local Government Area of Borno.
Eight policemen, three soldiers, and four Civilian Joint Task Force personnel died in the attack, local online newspaper Premium Times reported, citing security sources. Borno is the insurgency's birthplace and the state worst hit by the conflict.
"The terrorists made away with an armoured personnel carrier, a gun truck and six sports utility vehicles in the convoy", the source said.
"The attack on the convoy of the governor of Borno State, His Excellency, Babagana Zulum on Friday which left some soldiers and police officers dead with unspecified number of people injured is most disturbing especially coming just barely two months after the convoy of the governor suffered similar fate in the state".
The convoy, according to some of the people who returned to Maiduguri on Sunday evening from the tour, was shot at by suspected Boko Haram terrorists.
Civilians plying highway linking Monguno and the regional capital Maiduguri said the jihadists set up daily checkpoints, robbing, killing and abducting passengers.
The Islamic State (IS) group said it was behind the attack, claiming 30 people had been killed.
Local authorities have been encouraging the displaced to go back to the homes despite concern from aid agencies of the security risks to which the returnees would be exposed.
President Muhammadu Buhari "urges security and intelligence agencies to intensify efforts to check sabotage, sanitize the roads, venues and locations well in advance of returning IDPs (internally displaced people)", a statement issued by his spokesman said.
ISWAP splintered from the main Boko Haram group in 2016 and has gone on to be the dominant insurgent force in the region.