West Yorkshire Police has appealed for information about Yousuf and Muhammad Ahmad, who were last seen at their home in Liversedge at about 9:40am on Monday.
13-year-old Yousuf has been described as about 5ft 6ins tall, last seen wearing a Lyle and Scott grey hoodie, North Face trousers and black trainers. His brother, 10-year-old Muhammad, wears glasses
and is described as about 4ft 7ins tall. He was last seen wearing a black hoodie, grey tracksuit bottoms and black trainers with a white stripe.
The brothers are believed to be together. They had previously gone missing twice and were later safely found.
Police are making enquiries to locate them and have appealed for any information that may assist in the search. Information can be reported through the West Yorkshire Police website, or by contacting the police in Kirklees on 101.
