When battle-hardened Chadian troops overran a Boko Haram camp in northern Nigeria last week, they wanted to press deep into territory controlled by the Islamist group but Nigeria refused to let them. Having defeated al Qaeda in Mali two years ago, Chad's military believes it could finish off Boko Haram alone. It has notched up victories that have pushed the Nigerian militants back from the Cameroonian border. But with presidential elections this month, Nigeria is keen to press ahead with its own military campaign against Boko Haram, aiming to push it out of major towns before the March 28 ballot. In a country proud to be a major African power, it would be an embarrassment to President Goodluck Jonathan as he seeks reelection for a smaller nation to tackle Nigeria's security problems, diplomats say. In their forward base in the town of Gambaru on the Nigeria-Cameroon border, Chadian soldiers displayed dozens of guns seized from Boko Haram and a burnt-out armored vehicle painted with black and white Arabic script. "We turned back because Nigeria did not authorize us to go any further," army spokesman Colonel Azem Bermandoa said. Nigeria's spokesman for operations in the northeast, Mike Omeri, said cooperation between Chadian and Nigerian forces has brought some major military successes and any issues would be resolved via existing command structures. But the Chadians say there have been no joint operations between the two forces. Chad's offer to join a Nigerian offensive to capture Baga, site of one of Boko Haram's worst atrocities in January, was rebuffed, Bermandoa said. Officials from Chad, Niger and Cameroon say lack of cooperation from Nigeria has for months hampered efforts to put together a regional taskforce against Boko Haram. Chad was compelled to take unilateral action in January, under a deal that allows it to pursue terrorists into Nigeria, after Boko Haram violence started to choke off imports to its economy. With Niger and Cameroon deploying thousands of troops on their borders, blocking escape routes for Boko Haram, the tide may be turning. In what Nigeria has branded a sign of desperation, the Islamist group has carried out wave of suicide attacks and threatened to disrupt the election. Francois Conradie, analyst with South African-based NKC Research, said that if the current offensive can be sustained, Boko Haram could quickly be driven out of the remaining towns it holds. It would, however, remain a deadly rural guerrilla force. "All of this is good news for stability and will probably be to Mr Jonathan's electoral advantage," he said.