Police and the Department of Communities are asking for public help in locating a 10-year-old boy last seen in Perth's east on Boxing Day, but say they have found a second boy who was also missing.

The two children — 14-year-old Tyrell Hall-Alger and 10-year-old Declan Hall-Alger — were were reported missing from Lockridge on December 26.

Tyrell was located on Tuesday, but the search for Declan is continuing.

Declan is about 130cm tall, with blonde hair, light skin and a slight build.

Anyone with information on his whereabouts is urged to contact police immediately.