RAF Tornado aircraft have left the UK for Cyprus from where they will support efforts to deliver aid to refugees trapped on mountains in northern Iraq.

The jets will carry out surveillance ahead of further airdrops as the UN warned tens of thousands were trapped.

A "small number" of Chinook helicopters would also be sent for "further relief options", the Foreign Office said.

It comes as Islamic State (IS) fighters seized areas of Iraq, with reports of the slaughter of religious minorities.

Among those reportedly being targeted by the jihadists are Iraqi Christians and members of the Yazidi religious sect.

The UN Refugee Agency said about 35,000 people had escaped from the mountains into Syria and then into the Kurdistan region of Iraq in the past three days.

It said most were "exhausted, dehydrated and many have suffered sun or heat stroke". But it said "an estimated 20,000 to 30,000" Yazidis remain trapped without food, water or shelter.

The UN warned they needed "life-saving assistance", saying an estimated 700,000 Yazidis had been displaced.

Mirza Dinnay, a Yazidi relief worker, who was on board an Iraqi Air Force helicopter evacuating the trapped refugees, described the situation on the ground as "a genocide".

He told the BBC he had seen what looked like hundreds of bodies and said people had fought to get on board the helicopter after they landed.

US forces have carried out a number of air strikes targeting IS militants near Irbil, the capital of Iraqi Kurdistan, while drones have also fired on jihadist fighters.

BBC