Four Islamic State suspects held over 'US Embassy attack plot'
Turkish police have detained four Islamic State suspects as part of an investigation into a possible attack on the US Embassy in Ankara, the country's state-run news agency has reported.
The embassy was closed on Monday over an unspecified security threat.
The Anadolu Agency said police detained four Iraqi nationals in connection with the threat against the embassy. Two of them were detained on a bus at a security check on a road linking the Black Sea city of Samsun to Ankara. Two others were detained in Samsun.
The agency identified the suspects by their first names only.
Security was high outside the US embassy on Monday, and police searched pedestrians before allowing them to enter a street where the main gate is located.
The US embassy said on its web page late on Sunday that the mission would be closed due to a security threat, and urged US citizens to avoid the embassy as well as large crowds. It also advised citizens to "keep a low profile".
The Ankara governor's office said authorities had reviewed security in the capital and had taken additional measures, following intelligence provided by US "sources" about possible attacks against the embassy or where Americans are staying.
Earlier on Monday, police detained 12 IS suspects in Ankara and were searching for eight others, Anadolu reported, although it was not clear if these arrests were linked to the threat against the US Embassy.
The Ankara chief prosecutor's office said in a statement that all of the suspects captured in the police operation were foreign nationals. They were allegedly trying to recruit members for the Islamic State group and were in contact with people in "conflict zones", the statement said, without provide further details.
In 2013, a suicide bomber detonated an explosive in front of the US Embassy in Ankara, killing himself and a Turkish guard. Turkish officials blamed the attack on domestic leftists.
Turkey suffered a slew of deadly terror attacks in 2015 and 2016 carried out by IS or Kurdish rebels. An attack at a luxury Istanbul nightclub during New Year celebrations on January 1 2017, killed 39 people.