The pro-Kurdish news agency says a boat carrying about 300 people left Turkey on Friday morning, from a point close to Instanbul. There is no independent confirmation of the report, but pro-Kurdish sources seem to have had advanced warning that the two previous ships were on their way.

The Turkish coastguards said it would have stopped any vessel found to be carrying illegal migrants out of the country, but it knew nothing about this latest report. There's been a flurry of speculation in the Turkish media that large numbers of people are trying to leave, paying thousands of dollars each for the chance to reach Europe.

The Turkish government seems to be growing increasingly impatient about the causes of the exodus and the reaction in Italy, which has said it will welcome genuine political refugees. Turkey has now accused the Kurdish rebel group, the PKK, of setting up a quasi slave trade, manipulating economic migrants to further its own political goals.