Isis are threatening to capture a vital highway in Syria - the loss of which could push millions of refugees out of government-held areas

Islamic State (Isis) forces in Syria are threatening to capture a crucial road, the loss of which could touch off a panic and the exodus of several million refugees from government areas, in addition to the four million who have already fled. Isis fighters have advanced recently to within 22 miles of the M5 highway, the only major route connecting government-held territory in Damascus to the north and west of the country.