Istanbul, Aug 27 (IANS): Turkey has caught 16,423 illegal immigrants in its largest city of Istanbul since July 12 and they are set to be deported, authorities said on Tuesday.

The Istanbul Governor's office said in a written statement that security forces also captured 4,500 illegal Syrian refugees in the city with no official papers and transferred them to temporary refugee centres in several provinces across the country.

Meanwhile, Syrian refugees registered in other provinces were leaving Istanbul and returning to their places of registration in line with an earlier decision by the Governor's office, according to the statement cited by Xinhua news agency.

The deadline for illegal immigrants to leave Istanbul was extended to October 30 following consultations and evaluations with local authorities and several Syrian NGOs, said the statement.

In early July, the Governor's office ordered Syrian refugees who were registered somewhere else in Turkey to leave Istanbul and return to their places of registration by August 20.

There are a total of 1.06 million registered refugees in Istanbul, with 547,000 of them being Syrians, according to the authorities.

Turkish Interior Minister Suleyman Soylu said last week that similar actions would be taken in the capital city of Ankara and the northwestern province of Bursa as they were also overcrowded like Istanbul.