Two British medical students who joined Isis after studying in South Sudan have reportedly been killed during a firefight in Iraq.

Ahmed Sami Khider, from London, and Hisham Fadlallah, originally from Nottinghamshire, are thought to have died after a clash in the north of the country at the weekend.

Khider was killed by gunfire as he travelled in a convoy attempting to leave Mosul, which is the focus of efforts by the Iraqi army to oust the radical Islamist group.

It is not known if Fadlallah was killed at the same time.

They were among nine young British medical students – five men and four women – who travelled to the Middle East to help wounded people in Syria.

The group, all aged in their late teens and early 20s, allegedly flew to Istanbul from Sudan on 12 March in order to assist victims of war in Isis-controlled areas.

The students were born and raised in England, but had been studying medicine in the Sudanese capital Khartoum, where it is believed they were radicalised.

At least four members of that group have since been killed.

Shortly after arriving in Syria, Khider appeared in a propaganda film urging other Britons to travel to Syria and Iraq.

While many Isis films show pictures of masked men posing with guns, the softly spoken son of a doctor appealed for fellow UK doctors to join him in building a new society in a propaganda clip released by the group.

In pictures: Isis' weapons factories Show all 11 1 /11 In pictures: Isis' weapons factories In pictures: Isis' weapons factories A mortar round fin manufactured by Isis in Gogjali, Mosul, November 2016 Conflict Armament Research In pictures: Isis' weapons factories Isis rocket components discovered in Gogjali, Mosul, Iraq in November 2016 Conflict Armament Research In pictures: Isis' weapons factories Isis mortars discovered near Karamlais, Iraq, in November 2016 CAR In pictures: Isis' weapons factories An Isis rocket launch frame in Qaraqosh, November 2016 Conflict Armament Research In pictures: Isis' weapons factories A memo from Isis' COSQC on quality control at a manufacturing facility in Gogjali, Mosul, November 2016 Conflict Armament Research In pictures: Isis' weapons factories Electrically-operated initiators manufactured by Isis in forces Gogjali, Mosul, November 2016 Conflict Armament Research In pictures: Isis' weapons factories Isis mortar tubes at a manufacturing facility in Karamlais, November 2016 Conflict Armament Research In pictures: Isis' weapons factories An Isis mortar production facility discovered in Gogjali, Mosul, in November 2016 Conflict Armament Research In pictures: Isis' weapons factories An Isis weapons manufacturing facilities near Mosul in November 2016 Conflict Armament Research In pictures: Isis' weapons factories Stocks of French-manufactured Sorbitol, Latvian potassium nitrate and Lebanese sugar at an Isis weapons factory in Iraq Conflict Armament Research In pictures: Isis' weapons factories A destroyed Isis weapons facility in Qaraqosh, Iraq, November 2016 Conflict Armament Research

"There is a really good medical service being provided here, lots of hospitals … Paediatric hospitals, with specialised doctors," said the former student of Wallington County Grammar School in south London, sitting behind a desk in a wood-panelled office with a stethoscope around his neck.

The son of a doctor, who finished his UMST medical degree in July 2014, added: "Dear brothers and sisters, we as Muslims and as doctors have a great responsibility.

"All you are doing is sitting in the West in the comfort of your homes. Use your skills and come here."

The death of the pair follows news last week that a British bomber, named by Isis as Abu Zakariya al-Britani, blew himself up in an explosives-laden vehicle in a village south of Mosul.

The former Guantanamo Bay detainee, who was reportedly paid as much as £1m in compensation from the British Government after his release, was suspected of terrorism by the Americans but freed from the US detention centre in 2004.

The 50-year-old Muslim convert, from Manchester, was born Ronald Fiddler but also went by the name Jamal al-Harith.

Around 850 individuals of national security concern have travelled to join the conflict, according to figures published by the Government last year.

Of those, just under half have returned to the UK and approximately 15 per cent are dead.

A Foreign Office spokesman said: "We advise against all but essential travel to all of Iraq, and against all travel to large parts.