999 is the emergency telephone number for access to emergency services such as police, fire and ambulance.

From 9am - 9pm, on 9 June there was a 12-hour letter writing challenge dubbed '999' for the people of the Nuba Mountains in Sudan.

The event was hosted at the Turl Street Kitchen in Oxford by Humanitarian Aid Relief Trust (HART), founded by Baroness Caroline Cox, which works to provide aid and advocacy for those who are, or who have been, suffering oppression and persecution.

HART supports local partners in the Nuba Mountains region of Sudan, and Baroness Cox has recently returned from visiting people displaced from Blue Nile, Nuba Mountains and Abyei.

According to the HART Facebook page, "Throughout the day there was a constant stream of letter writers, just members of the public willing to raise their voices for the people of the Nuba Mountains who have not and will not be forgotten.

"Every new person we spoke to was surprised and shocked to hear about horrific suffering the Nuba people are enduring and that the UK government and media is not doing more to speak out about what is happening."

It continued: "During the afternoon we were lucky enough to have a visit from five Sudanese diaspora from London and Oxford. Several of which were from the Nuba region and spoke to us about the situation there and their appreciation for our work in writing to MPs (Members of Parliament) and for speaking out."

5 June marked the first anniversary of fighting starting in the Nuba Mountains where the Nuba people have been purposely driven from their homes by their own government, the Facebook page stated.

It said: "They are struggling to survive with no access to humanitarian aid and little pressure from the UK media or government to help change this."

The 9 June event in Oxford was supported by HART and AEGIS, an international organisation working to prevent crimes against humanity and genocide.

Since 2004, Sudan has been a major focus of Aegis' advocacy. This work is now informed by Dr Mukesh Kapila, former Head of the United Nations in Sudan, who joined the team as Special Representative on Crimes Against Humanity and who recently returned from seeing the destruction in the Nuba Mountains first hand alongside Aegis Trust CEO, Dr James Smith.

Baroness Cox's international humanitarian work includes serving as non-executive director of the Andrei Sakharov Foundation, trustee of MERLIN (Medical Emergency Relief International), and the Siberian Medical University, and Chief Executive of HART (Humanitarian Aid Relief Trust).

Her humanitarian work has taken her on several missions to conflict zones, including Armenia, the Sudan, Nigeria, the Burmese jungles and Indonesia.

She recently visited North Korea, to help promote parliamentary initiatives and medical programs and has been instrumental in helping change policies for orphaned and abandoned children in the Former Soviet Union.