Saudi Arabia's King Salman has ordered the transfer of conjoined twin brothers Yousuf and Yassin Abdulrahman from Yemen to the King Abdulaziz Medical City in Riyadh for possible separation surgery. The announcement of their move to the Saudi hospital, which is run by the country's National Guard, was made on Monday. Previous successful operations at the hospital to separate conjoined twins have required the efforts of dozens of specialist surgeons and lasted more than 10 hours. The announcement was made by Royal Court advisor Dr Abdullah bin Abdulaziz Al Rabeeah, who is also head of the surgical team for separating conjoined twins In addition to these roles, Dr Al Rabeeah is supervisor general of the King Salman Humanitarian Aid and Relief Centre. The brothers were born fused at the cranium, a condition known as "craniopagus twins". They are expected to arrive in Saudi Arabia with their parents within the next few days. Dr Al Rabeeah said the humanitarian gesture towards the “brotherly Yemeni neighbours” is an extension of King Salman’s efforts to help people around the world. He said that King Salman has ordered the medical team to proceed quickly and provide the twins with the best care. This is part of the Saudi national programme for separating conjoined twins from different parts of the world. Saudi Arabia covers all expenses for travel and medical care for the rare condition. So far, the country has assessed 108 cases from 21 countries. In January, it flew in Yemeni conjoined twins from Mukalla in Hadramout to the King Salman Air Base in Riyadh for examination. Conjoined twins occur in about one in every 2 million births. _________________