Seven traders found in possession of banned plastic bags were arrested on Wednesday in Mbale town, Vihiga County.
There has been concern about plastic bags smuggling syndicates creeping back into towns in western Kenya.
Kenya implemented a total ban on single-use plastic bags in 2017. However, the commodity is still being sold, even though not in the open.
The suspects were nabbed after National Environment Management Agency (Nema), together with the police, conducted a crackdown on traders using the banned bags.
The crackdown came after complaints that banned plastic carrier bags were still in circulation in most parts of western Kenya.
The swoop was led by Nema Vihiga County Director Hesborn Monda.
"We have arrested the seven who were using the banned plastic bags. This confirms that some unscrupulous traders still flouting the law on this," Mr Monda said.
The traders are using plastic bags despite the hefty penalties imposed by the government on individuals found flouting the regulation.
In 2017, the Environment Ministry announced that those found in possession of the banned bags would be fined Sh50,000 while manufacturers flouting the ban would pay penalties of between Sh2 million and Sh4 million.
According to Monda, most of the plastic bags are illegally imported through porous border points and sold in backstreet markets in Mbale, Chavakali and Luanda in Vihiga and others around Kakamega, Busia, Bungoma, Trans Nzoia and Uasin Gishu counties.
Those arrested will be arraigned to answer to the charges of flouting the plastic ban laws.
Mr Monda reminded the traders that the plastics ban is effected to save the environment.
The crackdown was also carried out in neighbouring Kakamega, Nandi and Uasin Gishu counties.