Nigeria's military says it has arrested another 49 members of the Islamist militant group known as Boko Haram.
The military said Wednesday it captured the suspected militants in Yobe, one of three northeastern states placed under emergency rule as part of a military offensive against the group.
The military says it has captured more than 150 Boko Haram members since it launched the offensive last month.
Its claims of success have been impossible to verify because of downed phone networks and restricted access to the conflict zone.
Meanwhile, President Goodluck Jonathan has formally declared Boko Haram and its suspected splinter group Ansaru to be outlawed terrorist organizations.
Nigerian authorities say Ansaru is responsible for kidnapping and killing Westerners. The group is believed to have ties to al-Qaida's North African wing, al-Qaida in the Islamic Maghreb (AQIM).
The terrorist designation allows the government to impose prison sentences of a minimum of 20 years on group members or supporters.
Boko Haram launched its uprising in 2009. The shadowy group wants to impose Islamic law in northern Nigeria. Human Rights Watch says more than 3,000 people have been killed in Boko Haram-related violence, including hundreds of killings by military forces fighting the group.
According to Peter Pham, head of the Central Africa program the Atlantic Council, a Washington-based international security think tank, the Nigerian government's crackdown may not be effective at ending longtime unrest in the north.
"The state of emergency in three northern states ... inflames the population because the insurgents are hidden among the population," Pham recently said during an interview with Voice of America’s Encounter
. "No doubt the military has killed some insurgents but, in the process, there are extremely credible reports that they are also killing innocent civilians as well, and that's not going to win hearts and minds, which is the key of any counter-insurgency."
Pham says the clashes between government forces and militants have also created a refugee crisis in the region, with thousands of Nigerians fleeing into neighboring Niger.
Some information for this report was provided by AP.