Twenty-nine people were on Tuesday fined Sh50,000 each or serve one year in jail by a Mombasa court for possessing plastic bags after they pleaded guilty.
Thirty-one people were arrested in the coastal city on Monday for being in possession of plastic bags.
Three other people denied the charges and were released on a Sh400,000 bond and a surety of a similar amount after denying the charges.
The individuals were arrested in a crackdown by National Environment Management Authority (Nema) and Mombasa County Inspectorate Department.
Nema enforcement officer Robert Orina said the team conducted the crackdown in Majengo Market and Tudor.
He said two of those arrested were suppliers of the banned bags.
Mombasa Inspectorate director Mohamed Amir told the Nation the county would not tolerate the use of plastic bags and would work with the national government to enforce the ban.
He warned residents against using the banned bags.
“I want to ask the residents to help us secure our environment,” Mr Amir said.
He urged locals to use reusable bags to conserve the environment.
Nema earlier asked Kenyans to use bags made from paper, cloth and other biodegradable material.
On Monday, Nema and Mombasa County officials asked those still having plastic bags to surrender them to the authority or face arrest.