At least 20 people have been killed in one of two car bomb blasts in the eastern Syrian city of Hasaka, state television reported.
One of the explosions reportedly occurred in the north of the city, and the other in its centre.
On a visit to Jordan, David Cameron says that the EU must "follow Britain's lead" and fund more refugee camps around Syria.
The prime minister has insisted the UK will not participate in plans to redistribute 160,000 refugees who have arrived in Europe.
Train traffic with Austria suspended as German authorities seek to reduce the number of asylum seekers arriving in the country.