PITTSBURG, Calif. (KRON) — The Pittsburg Police Department is searching for a missing, elderly man with dementia, police said Thursday. Police referred to the man as Mr. Ziegler. He is 74 years old.

Ziegler is 5-foot-5, 160 pounds with pepper-gray hair and brown eyes, police said. He has been missing from Diamond Healthcare Center on 2351 Loveridge Road since 1:00 p.m. Thursday.

The Oakland Police Department is also looking for a missing person, Baozhu Guan, 69. California Highway Patrol issued a Silver Alert for Guan on Thursday.

Guan has been missing since Tuesday morning and suffers from Alzheimer’s. She is five feet tall, weighs 120 pounds and has gray hair and brown eyes. She is believed to be on foot and was last seen wearing a long-sleeved shirt, red or blue jacket and a straw hat.