Abuja - Nigerian soldiers have killed three members of Islamist militant sect Boko Haram and arrested 25 more in the northeast, the army said on Tuesday, two weeks after the launch of a major ground and air offensive to crush the group's four-year rebellion.
President Goodluck Jonathan declared a state of emergency in three northeast states of Borno, Yobe and Adamawa on May 14 and ordered thousands of additional troops to the area where Boko Haram has established bases and weapons dumps.
The assault in the remote semi-deserts along the borders with Cameroon, Chad and Niger is Jonathan's biggest effort yet to end fighting in which thousands have died. Security sources say soldiers from Niger and Cameroon are also involved.
It follows a surge in violence in Nigeria's northeast by Islamists who want to establish an Islamic state there.
Military spokesman Chris Olukolade said one member of the security forces was killed during the operation near the town of Maiduguri. He did not say when the incident happened.
Olukolade said the multi-national task force had also intercepted messages sent between insurgents regrouping near the Cameroon border urging them all to "fight to the end".
"The attempt by some of them to heed the call was foiled during the weekend ... Troops carried out an operation which resulted in the capture and destruction of the insurgents' assembly points," he said.
Phone and Internet services have been disconnected for 12 days in northeast Borno state, of which Maiduguri is the capital, making it impossible to verify the military's statement.
Rights groups are concerned that the communications blackout and curfews will make it difficult for civilians to access food, water and healthcare in one of the poorest regions of the country.
They also worry that the secrecy of the operation means soldiers may carry out human rights abuses with impunity. There is previous evidence of the army carrying out extra-judicial killings and torture, rights groups say.
The army denies it has carried out any human rights abuses.