The US consulate in Istanbul remains open even though Germany, Britain and the Netherlands have closed their diplomatic missions after threats of terrorist attacks in the Turkish capital.

A deputy State Department spokesman said the US mission in Turkey issued security warnings this week about possible terrorist attacks on religious sites and diplomatic missions in busy areas of the city.

He added that the Turkish authorities are investigating due to the security warnings.

In the past few days, there have been threats of attacks in Istanbul on social networks, after protests where the Koran was burned in some European capitals last month.

The Turkish president Recep Tayyip Erdogan said that Sweden should not expect support from Ankara to join NATO after protests by anti-Islamic activists and pro-Kurdish groups in Stockholm.

Erdogan with a new appeal to Sweden and Finland: Hand over the terrorists if you want to join NATO