A freighter carrying grain from Ukraine ran aground in the Bosphorus Strait.
The reason was a malfunction at the rudder, the state news agency Anadolu reported on Thursday evening.
The strait was initially closed to shipping.
The ship "Lady Zehma" has loaded 3,000 tons of corn and is on its way to Italy, according to the Istanbul-based control center for Ukrainian grain exports.
The Bosphorus and the Dardanelles are important thoroughfares connecting the Black Sea and the Mediterranean.
According to Turkish authorities, more than 40,000 ships pass through the Bosphorus every year.
Agricultural exports via the Ukrainian Black Sea ports were blocked for months due to the Russian war of aggression.
War opponents Ukraine and Russia signed an agreement separately with Turkey on July 22, through UN mediation, to allow grain exports from Ukraine from three ports.
It is estimated that more than 20 million tons of grain products are stored in Ukraine.