Witnesses said the supporters of AL candidate Abdur Rashid launched an attack and vandalised the houses of Hindu community people as they were supporters of independent candidate JM Rashid.
Officer-in-Charge of Sadar Police Station Mizanur Rahman Khan said additional forces were deployed in the area to fend off any unwanted situation.
Earlier, in the 3rd phase, elections to 117 upazila parishads across the country ended in the evening amid sporadic violence and allegations of vote rigging and other irregularities.
The first phase and second phase elections were held on March 10 and March 18 respectively, while the fourth phase polls are scheduled to be held on March 31.
The first upazila election was held in 1985, while the following three were held in 1990, 2009 and 2014.