At least 14 polling stations in Bangladesh have been set on fire, including one on the outskirts of the capital, Dhaka.
The wave of attacks came a day before voting began in the country’s election.
On Friday, a busy commuter train was allegedly set on fire, killing four passengers.
Most opposition parties are boycotting the election, in which Prime Minister Sheikh Hasina is set to win a fourth consecutive term.
Police say a prominent opposition politician, Nabiullah Nabi of the Bangladesh Nationalist Party (BNP), and six other party activists have been arrested on suspicion of involvement in Friday’s fire on a commuter train in central Dhaka.
Samanta Lal Sen, a senior official at the Dhaka hospital, says eight people have been critically injured.
Local media say a Buddhist temple in the south-eastern city of Chittagong has been torched, and the Election Commission says a local party office of the ruling Awami League has been attacked.
The BNP has asked voters to boycott the poll and called a two-day strike across the country.
The ruling Awami League has accused the BNP of trying to disrupt the election by unleashing a “reign of terror on innocent people.”
On Friday, the UN Special Rapporteur, Clément Nyaletsossi Voule, said he was “deeply disturbed” by the repressive environment surrounding the polls.
With direct inputs from BBC.
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