MAIDUGURI/MAROUA Nigerian soldiers recaptured two towns from Boko Haram on Monday as U.S. and regional troops began war games in neighbouring Chad in a growing international campaign to counter the Islamist group.
But militants from Boko Haram, which has killed and kidnapped thousands in a six-year-old insurgency in Africa's most populous nation, still managed to attack a military camp near Waza in northern Cameroon, killing five soldiers.
After coming under fire, the soldiers in Cameroon, where 100 people were massacred in a Boko Haram border raid two weeks ago, hit back in an intense battle lasting hours, army sources said.
"Five soldiers killed, seven wounded and over 80 Boko Haram assailants (were) killed in the waves of attacks," Colonel Didier Badjeck said in Maroua, a town just south of the Lake Chad region where Nigeria, Niger, Chad and Cameroon meet.
Monday's strike beyond Nigeria's borders is typical of Boko Haram's recent tactics, hitting troops gearing up for a coordinated campaign against its effort to build an Islamic caliphate in northeastern Nigeria.
In Nigeria itself, where the insurgency was cited as the main reason for postponing a Feb. 14 election by six weeks, the military said it was going on the offensive after months of criticism that its response has been insufficient and inefficient.
Troops backed by air strikes recaptured the northeastern town of Monguno, on the shores of Lake Chad, it said in a statement. Monguno was seized by Boko Haram in an offensive last month that also targeted Maiduguri, the regional capital.
"The air and land operation is continuing with aggressive advance towards other designated communities and locations meant to be cleared in the ongoing offensive against the terrorists," defence spokesman Major-General Chris Olukolade said.
The army had also seized the nearby town of Marte, the statement said.
In a sign of growing regional solidarity in the face of Boko Haram, presidents from the 10-nation Economic Community of Central African States (CEEAC) pledged on Monday to create an emergency fund of 50 billion CFA francs ($87 million).
The funds would go towards military, medical and logistical support, members said in a statement.
Coinciding with the Nigerian offensive, Chad launched a U.S.-backed counter-terrorism exercise involving 1,300 soldiers from 28 African and Western countries that has been billed as a warm-up for a multi-pronged onslaught against Boko Haram.
The annual "Flintlock" exercises began in 2005 in an attempt to improve cross-border cooperation in Africa's arid Sahel belt, a region prey to al Qaeda-linked and home-grown Islamists, separatist insurgents and criminal trafficking gangs.
But concern and outrage over Boko Haram has mounted, particularly after the kidnapping of more than 200 schoolgirls from the town of Chibok last April, and the group has become the primary target of the exercises.
Chad suffered its first known lethal attack last week in what appeared to be a revenge strike for deploying its forces in the Nigerian border town of Gambaru.
"This exercise to a large extent can be considered a warm-up to enable our special forces to learn techniques in the fight against terrorism," Chadian Brigadier General Zakaria Ngobongue said in a speech to mark the start of the exercises.
More than 250 U.S. troops will take part in the three-week training drill, helping improve intelligence-sharing, patrols, desert survival techniques, airborne operations and marksmanship, the U.S. military said.
Other nations taking part in Flintlock include Algeria, Burkina Faso, Cameroon, Mali, Mauritania, Niger, Nigeria, Senegal and Tunisia.
(Additional reporting by Dan Flynn, Julia Payne, Bate Felix, Tansa Musa and Tim Cocks; Writing by Ed Cropley and Emma Farge; Editing by Andrew Roche)