British police say they are investigating the disappearance of a family of 12 feared to have traveled to Syria.

Bedfordshire police say the group from Luton, near London, includes three children, including a one-year-old baby, and two grandparents. The family was reported missing after they failed to return home from a holiday in Bangladesh in May.

Police said Wednesday they are working with the family's relatives to probe whether the family had crossed into Syria.

The family was the latest in a growing number of Britons feared to have traveled to Syria to join extremists there. British police say more than 700 potential terror suspects have traveled to Syria to fight or support militants, and only about half are believed to have returned.