Security was strengthened across Bangladesh on Wednesday after a religious minority group came under attack by opposition activists who boycotted Sunday’s elections, police said.

More than 112 homesteads belonging to the Hindu community were torched, after the elections that left 20 people dead across the country.

“We have launched operations to capture the attackers,” said Joydev Bhadra, police chief of the south-western district of Jessore.

Supporters of the Bangladesh Nationalist Party (BNP) of former prime minister Khaleda Zia, and its ally Bangladesh Jamaat-e-Islami, allegedly the carried out the attacks on Hindus, seen as supportive of the ruling Awami League of Prime Minister Sheikh Hasina.

Police also arrested four BNP leaders, including one adviser to Ms. Zia, on Tuesday after Ms. Hasina warned of using an iron fist to deal with the unrest.

The opposition boycotted the elections and tried to stop the voting.

It called a new strike this week to demand fresh elections under a non-partisan caretaker administration.

“Additional police were deployed in all strategic points to thwart any attempt of vandalism,” said police officer Kripasindhu Bala.

Awami League won 232 out of 300 parliamentary seats in Sunday’s elections.