David Cameron joins other western leaders in calling for the return of the girls kidnapped by Boko Haram, but experts warn it will not be easy to track them down.
Mr Cameron was handed a sign bearing the slogan #BRING BACK OUR GIRLS – a reference to the social media campaign which has attracted support from many celebrities and activists in recent days – in a BBC interview.
The prime minister said Britain had offered to send specialists to help the Nigerian authorities find the group of more than 270 girls abducted from their boarding school by the Islamist group on 15 April.
He said: “I rang the Nigerian president to offer anything that would be helpful, and we agreed to send out a team that includes some counter terrorism and intelligence experts to work alongside the bigger American team that’s going out there, and we stand ready to do anything more that the Nigerians would want.
“We can’t just sort of, you know, pile in and do whatever we’d like. It’s immensely complicated because they’re in this deep, probably in this deep area of jungle, that is three times the size of Wales but it’s good that efforts are being stepped up and we’ll do what we can.”
The US defence secretary, Chuck Hagel, also said the US has offered to help, but stressed that “there’s no intention at this point to be putting any American boots on the ground”.
He added: “It’s going to be very difficult. It’s a vast country. So this is not going to be an easy task but we’re going to bring to bear every asset we can possibly use to help the Nigerian government.”
On Sunday, Israel also said that is stood ready to help the Nigerian government find the girls.
Mr Cameron’s support for the #BringBackOurGirls campaign drew some criticism on Twitter.
The prime minister said he would “happily” join the campaign when handed the handwritten sign by CNN journalist Christiane Amanpour on BBC One’s Andrew Marr programme. He later tweeted a picture of them both holding up the sign.
Author David Cushman tweeted: “The point of a campaign like #BringBackOurGirls is for people like us to get people like you to do something – not just join.”
Novelist Jojo Moyes said: “The #BringBackOurGirls hashtag is great. But it worries me that David Cameron thinks holding it up on TV is really the best he can do.”
Archbishop of Canterbury Justin Welby, who has been involved in negotiations with violent groups in Nigeria’s Niger Delta and a precursor to Boko Haram, said the girls were at “colossal risk”.
He told the BBC: “They are in the hands of a very disparate group which is extremely irrational and difficult to deal with and utterly merciless in the example it has shown in the past.
“It is a huge concern and it is wonderful this global campaign has got going to support them.”
On Sunday morning, Christians in the Nigerian capital Abuja prayed for the missing pupils in church services, while the police allowed an “illegal” #BringBackOurGirls demonstration to go ahead without intervening.