British police are appealing for information on a family with four children who may have travelled to Syria.

Thames Valley Police say Asif Malik, his partner, Sara Kiran, and four children aged between 12 months and 7 years old have not been seen in England since early April.

Acting Deputy Chief Constable John Campbell told reporters Sunday that police are concerned about anyone intending to travel to parts of Syria controlled by the Islamic State group. He says it is "an extremely dangerous place and not a place where young children should be taken."

Authorities say that there was no suggestion the family was doing any fighting in Syria, and it was unclear whether they were sympathetic to members of IS or Syrian President Bashar al-Assad.