Nigerian police offered a 50 million naira ($300,000) reward on Wednesday to anyone who could give information leading to the rescue of more than 200 schoolgirls abducted by Islamist rebels.
Last month's mass kidnapping by militant group Boko Haram triggered an international outcry and protests in Nigeria, piling pressure on the government to get the girls back.
Public anger mounted after locals on Tuesday said another eight girls had been seized from the same remote northeastern area by suspected members of the group, which is seeking to carve out an Islamist state.
Police listed six phone numbers in their statement and urged Nigerians to call in with "credible information".
Boko Haram leader Abubakar Shekau has threatened in a video to sell the girls abducted on April 14 from a secondary school in the village of Chibok "on the market".
The United States has offered to send a team to Nigeria to help the search efforts.
The kidnappings, and other attacks by Boko Haram, have overshadowed Nigeria's hosting of the World Economic Forum (WEF) which is due to start on Wednesday evening.
($1 = 161.45 naira)