Police have arrested at least 12 people from various polling centres during the Comilla City Corporation elections on Wednesday.
A mobile court delivered sentences ranging from three days to three months against them, said Comilla Deputy Commissioner Kamrul Hassan.
Those arrested and sentenced are all outsiders, not voters, he said.
He added that they have been sent to jail.
Earlier, the district administration had announced that outsiders will not be allowed in the city during the polls as part of the security measures undertaken to ensure a peaceful voting environment.
Comilla city went for its third polls since its formation in 2011. A total of of 229,920 voters will exercise their right to vote using EVMs at 105 centres with five candidates vying for mayor.
The last Comilla city election was held on Mar 30, 2017, which saw then-BNP leader Sakku getting elected mayor for a second term.