There was no claim of responsibility for the blast at the Phramongkutklao Hospital.
The blast left 20 people dead, more than half of them foreigners, and over 120 injured.
At least 20 people were killed in the August attack.
Arrest warrants were issued for both the woman and man on charges of possessing unauthorized explosives.
No one has claimed responsibility for the blast, which killed 20 people and wounded over 120.
"Sometimes there are 20 cameras on the street but only five work. We have to waste time putting the dots together."
Twenty people were killed in the blast at the popular Hindu shrine.
No one has claimed responsibility for the blast, Thailand's worst bombing, at a popular Hindu shrine crowded with tourists.
Thailand's police chief said on Thursday at least 10 people were suspected of involvement in a bomb attack in Bangkok this week that killed 20 people, more than half of them foreigners.
Authorities are hunting a man seen in a bright yellow shirt.