The man who shot and killed partygoers in the Turkish city of Istanbul on New Year’s Eve is probably of ethnic Uighur origin, police have said, as several more people are detained over the possibility they helped him carry out the attack.

Deputy Prime Minister Veysi Kaynak told state media on Thursday that security services now have a good idea of where the suspect is hiding. Authorities had previously released photographs of the man and said they had his biometric records, but have not released his name.

Mr Kaynak described the man as a “specially trained” member of a cell who carried out the attack alone, but may have been assisted in planning by others. Dozens of people have been detained in connection to the investigation since Saturday’s attack.

Isis claimed responsibility for the shooting at the upmarket Reina nightclub that killed 39, saying it was revenge for Turkish military involvement in Syria.

Police carried out a dawn raid in a town near Istanbul on Thursday, detaining suspects thought to be connected to the attack, state-run Anadolu news agency said.

People of Uighur ethnicity were among those detained.

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Uighurs are a largely Muslim, Turkic-speaking minority in far western China with significant diaspora communities across central Asia and Turkey.

A security source and media reports have said that the gunman is thought to be a national of a central Asian country.