U.S. Embassy warns citizens about 'credible threats' in Turkey

A full moon rises over the Bosphorus bridge in Istanbul September 8, 2014. REUTERS/Murad Sezer

ISTANBUL (Reuters) - Turkish police carried out a controlled explosion of a bag left in Istanbul's popular Taksim square on Saturday, a Reuters witness at the scene said, hours after the U.S. embassy warned of "credible threats" to tourist areas.

Police cordoned off Taksim, a square lined with hotels and restaurants frequented by tourists, while a member of the police bomb squad was seen opening what appeared to be a bag, the witness said. The bomb squad later detonated it in a controlled explosion, causing a loud boom to echo across the square, the witness said.