UPDATE 1-Nigerian troops evacuate town in security operation - U.N.

Nigerian troops evacuated the entire population of a town of 10,000 people in northeastern Borno state without warning on Monday before an operation against militants, the United Nations said on Thursday. The military relocated the people of Jakana to a camp in the city of Maiduguri about 40 km (25 miles) away, some arriving with "nothing, not even shoes on their feet," the United Nations said in a statement.

The northeast is the battleground in Nigeria's decade-long fight against Islamist insurgencies Islamic State West Africa Province and Boko Haram. A surge in militant attacks in December in which towns and military bases were overrun saw tens of thousands of civilians fleeing into Maiduguri and swelling the population of existing camps.

"The entire town of Jakana was emptied, and people were forced to move to Maiduguri with very little time to collect personal belongings," Edward Kallon, U.N. humanitarian coordinator for Nigeria, said in the statement. Jakana residents said the military was screening the population for Boko Haram members.

Last June, the Nigerian government ordered thousands of people to leave the relative safety of their camp in Maiduguri to live in a town in an unsafe area. In September, the town was attacked, forcing the population to flee. (Reporting by Tom Miles in Geneva; Writing by Paul Carsten; Editing by Angus MacSwan)