Story highlights Islamist terror group abducted 97 people last week, security sources say

Chadian security forces stopped a convoy along Lake Chad

85 of the hostages in the convoy were rescued, authorities said

Chadian troops have rescued 85 Nigerians kidnapped last week by the Islamist terror group Boko Haram , security and human rights sources in Nigeria said Saturday.

Dozens of Boko Haram insurgents stormed the Doron Baga fishing and farming village on the shores of Lake Chad late Sunday through Monday and took away 97 young men and boys plus several women, residents said. The raiders killed 28 residents and burned scores of homes, according to residents.

The hostages were loaded onto motorboats and ferried into neighboring Chad, with residents saying they feared the hostages would be forcefully conscripted as foot soldiers.

Chadian security officials reported intercepting a convoy of buses carrying 85 Nigerians" believed to have been kidnapped by Boko Haram terrorists from Baga," a Nigerian security source said.

"The convoy being led by six Boko Haram gunmen was stopped on the Chadian part of the border along Lake Chad for routine checks and the huge number in the convoy raised suspicion," said the source, who asked not to be named because he was not authorized to speak on the issue.

An official of the National Human Rights Commission (NHRC) in Maiduguri confirmed the rescue of the 63 male and 22 female hostages.

The source, who asked that his name not be used, said more than 30 hostages were still being held by Boko Haram. He said their captors sped off with them in motorboats when they spotted the convoy being questioned by Chadian soldiers.

Boko Haram has been waging a five-year armed insurgency to create an Islamic state in northern Nigeria. The group has carried out series of abductions, including the April kidnapping of more than 200 schoolgirls from a boarding school in the town of Chibok.

Boko Haram uses its hostages as conscripts and sex slaves, according to authorities. They say Boko Haram has killed more than 12,000 people and displaced more than half a million residents.