Military officials say a truck carrying refugees to a newly liberated town exploded a land-mine in northeast Nigeria and wounded several people.

It's the third attack in two weeks on returnees blamed on Boko Haram Islamic extremists. A taxi-van of refugees exploded Oct. 12 outside Maiduguri, killing eight people and an armored personnel carrier escorting refugees hit a land-mine, injuring several soldiers.

Maiduguri is the biggest city in the northeast, the birthplace of Boko Haram and houses more than 1 million refugees from the 7-year Islamic uprising.

Nigeria's military said Wednesday's explosion hit a truck in a military escorted convoy of 200 vehicles traveling from Maiduguri 140 kilometers (88 miles) northeast to Gamboru-Ngala.

The attacks come as Nigeria's government hopes to persuade hundreds of thousands of refugees to return home.