Security forces in Nigeria are still searching for 100 teenage girls abducted from a school in the northeastern state of Borno.
Their kidnap happened in an area where the Boko Haram group has been extremely active.
Officials say one of the trucks used to carry the girls away late on Monday has been found abandoned and it is thought they are now in a forest near the border with Cameroon.
Boko Haram is a fierce critic of Western-style education and educational institutions are frequently targetted.
Bombings blamed on the group killed more than 70 people in the capital city of Abuja earlier on Monday.
A BBC correspondent said it will be hard for any rescue effort to succeed without further endangering the girls' lives.