LONDON (AP) — British counterterrorism officers say they believe that two missing 16-year-old twin sisters who disappeared from their home in Manchester have traveled to Syria.

The two girls left Britain on June 26 and flew to Turkey, where police believe they crossed the border to Syria.

Detective Chief Superintendent Tony Mole from the North West Counter Terrorism Unit said Wednesday the sisters have put themselves in danger. But he said police do not know why they traveled there or who they are with.

The counter terrorism unit is now investigating whether the girls had help travelling to Syria, which is engulfed in civil war.

Security officials in Britain say several hundred Britons have traveled to Syria to support rebels fighting the government of President Bashar Assad.

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