The PSNI say police officers are searching the Six Mile Water river near Pauline Carmichael’s house.
She has been missing from her home in Hillside, Antrim, since Monday night.
The 61-year-old was wearing pink pyjamas when last seen.
She’s described as being 5ft 4ins tall with blonde hair.
A police spokesperson said officers are concerned her safety.
The two men arrested are aged 37 and 59.
Detectives have appealed for anyone with information to contact them on the 101 non emergency number.