the Syrian government forces and 70 Islamic State fighters had been killed in clashes since Saturday.

The official news agency SANA reported on Monday that government forces had recaptured some residential areas taken by Islamic State in Begayliya, near the city of Deir al Zor, and killed a number of fighters.

On Tuesday, Islamic State said it had made further gains against government forces near Ayyash, and had captured two military vehicles.

Deir al-Zor province links Islamic State’s de facto capital in Raqqa with territory controlled by the group in Iraq. The group made previous attempts to take over government-held areas of the city in 2015, including the airport.

The United Nations has warned that around 200,000 besieged residents in Deir al-Zor face severe food shortages.

Islamic State kidnapped at least 400 civiliansDozens of world leaders, including Prince Charles, President Vladimir Putin and US Vice President Mike Pence, gathered in Jerusalem on Thursday to mark the 75th anniversary of the liberation of Auschwitz concentration camp in what Israel has billed as its biggest ever international event.

Delegations from nearly 50 countries, including 41 heads of states, congregated Yad Vashem Holocaust memorial centre for the fifth World Holocaust Forum to remember more than one million people, most of them Jews, who were held and murdered in Auschwitz-Birkenau.

There Israeli President Reuven Rivlin and Prime Minister Benjamin Netanyahu urged the attendees and the world to help battle a rising tide of anti-semitism. Mr Netanyahu used his speech to highlight the Iranian leadership, calling it "the most anti-Semitic regime on the planet" and "the tyrants