(REUTERS) - Many left it all behind. They found shelter in Niger's arid south-eastern region amid a wave of new attacks by Boko Haram in north-east Nigeria.

"It has been exactly 11 days since we fled from our village. Boko Haram came," said Nigerian refugee Lagari Fogo. "We fled during the night. Personally, I was very scared and I'm still scared. We left everything behind."

After Boko Haram's bloody six-year campaign to carve an Islamist state, they now claim an area the size of Switzerland.

Recently elected Nigerian President Muhammadu Buhari in Washington vows to defeat the Islamist group.

"We are confident that we will defeat terrorism in our country and region, because we have the will to win this fight," he said.

It's a pledge that cannot come soon enough for those who escaped the violence with little more than lives.