Family goes missing enroute to Syria

A family from Slough has been missing for nearly two weeks, with police suspecting they may be traveling to Syria. The family's flat was found with signs of forced entry, and neighbors are concerned, especially for the young children. The family is believed to have traveled from Dover to Calais and then across Europe, possibly reaching Budapest. Authorities have warned against traveling to Syria due to the risk of arrest. The family and friends of the missing individuals are urging them to return safely.

How long had the family been missing before the police began their search?

What did the foreign officers warn Britons about regarding Syria?