Under fire over its slow reaction over three British schoolgirls who reportedly fled to Syria to join the Islamic State, Scotland Yard on Tuesday defended its actions, saying it began a probe as soon as facts were established.
Turkish Deputy Prime Minister Bulent Arinc, accused the force of unnecessary delay by alerting them only three days later.
However, the Metropolitan Police said it began working with Turkish authorities a day after the girls went missing and as soon as they had established the facts.
Shamima Begum and Amira Abase, both 15, and Kadiza Sultana, 16, travelled to Istanbul on February 17.
They boarded a Turkish Airlines flight at Gatwick airport and would have required a visa to enter the country.
Arinc said: "It is a condemnable act for Britain to let three girls... come to Istanbul and then let us know three days later. They haven't taken the necessary measures. The search is ongoing.”
“It would be great if we can find them. But if we can't, it is not us who will be responsible, but the British.”
His comments came after UK police officers travelled to Turkey, although their role in the country has not been confirmed.
A Scotland Yard statement said: "Once we established that the girls had travelled to Turkey, police made contact with the foreign liaison officer at the Turkish Embassy in London on Wednesday, 18 February. Since then we have been working closely with the Turkish authorities who are providing great assistance and support to our investigation.”
House of Commons’ Home Affairs Committee chairman Keith Vaz said there needed to be “much closer cooperation” with Turkey in tackling the problem of people travelling through the country to Syria and Iraq.
British Prime Minister David Cameron has also urged airlines and internet companies to do more to prevent radicalised British teenagers travelling to the Middle East.
The three girls had been studying for their GCSEs, equivalent of Class 10, at BethnalGreenAcademy in Tower Hamlets area of east London.
A fourth girl from the school had travelled to Syria in December last year.
The school's head teacher has said that support was being offered to students and staff in the wake of the incident as students returned to the school after half-term holidays on Monday.
Mark Keary also stressed that there was no evidence that the "radicalisation" of the missing students took place at the school.
The girls' families, who have described them as bright “Straight A” students, have also issued moving public pleas for them to return home.
