Members of Girls' Brigade England & Wales are joining in with a social media campaign to pray and advocate for the schoolgirls kidnapped in Nigeria earlier this year.

Girls' Brigade International (GB) has produced a prayer resource with help from Alliance member Open Doors for members worldwide to use on Thursday, 11 September 2014, which marks 150 days since the young women were taken.

Claire Rush, participation and advocacy co-ordinator for GB England & Wales, says: "Thursday, 11 September marks 150 days since more than 200 Chibok young women, some of whom are members of GB, were kidnapped by Boko Haram. These young women have been silent for 150 days but we have a voice that can be heard. Let's raise our voice for the voiceless on 11 September."

Boko Haram, which means "western education is forbidden", is a militant Islamist group based in northeast Nigeria. The group has received training and funds from Al-Qaeda in the Islamic Maghreb, and was designated by the US as a terrorist organisation in November 2013. Membership has been estimated to number between a few hundred to a few thousand people.

On 14 April 2014 Boko Haram militants stormed an all-girl secondary school in the village of Chibok, in Borno state, Nigeria and packed the teenagers, who had been taking exams, on to trucks. They then disappeared into a remote area along the border with Cameroon.

The U.S. Commission on International Religious Freedom says that in recent years, Boko Haram has carried out dozens of attacks, killing thousands of people in schools, churches, police stations, government buildings and elsewhere. Targets include Christians, senior Islamic figures critical of Boko Haram and people the group believes to be engaged in "un-Islamic" behaviour.

The prayer resource can be downloaded for free from www.girlsb.org. GB would also like people to sign up for GB's Thunderclap, via Facebook or Twitter, here. Thunderclap is a website that allows people to pledge a social media post. All pledged posts will go out at the same time, on the same day, saying the same thing, in order to achieve the maximum impact.

Those aged 18 to 30 from GB England &Wales' advocacy group will also be writing a letter to the prime minister David Cameron to remind him about the missing girls, urging him to use his influence in the international community to ensure everything is done to get them home.