Police fired rubber bullets and tear gas at hundreds of opposition activists in Bangladesh on Sunday as a nationwide strike over the disappearance of a senior politician brought daily life to a halt.
More than a dozen people were injured, four of them seriously, police said, as violence erupted in the northeastern city of Sylhet, home to opposition leader Ilias Ali who has been missing for five days.
Rights groups have blamed security agencies for the disappearance of dozens of opposition activists over the past two years, alleging the victims have been abducted on government orders.
Police found Ali's car abandoned in an upmarket district of Dhaka on Tuesday night. His driver is also missing.
Ali, a regional head of the opposition Bangladesh Nationalist Party (BNP), is the highest profile opposition politician to have "disappeared" since Prime Minister Sheikh Hasina took power in January 2009.
The BNP has accused the elite Rapid Action Battalion of abducting Ali, an allegation it has rejected.
Police in Sylhet said clashes broke out after they were attacked by 800 opposition activists, forcing officers to retaliate with rubber bullets and tear gas.
"We've fired more than 50 rounds of rubber bullets and tear gas shells. But the clashes are still going on," deputy commissioner of Sylhet police Abdullah Al Azad told AFP, adding more than a dozen people were injured.
There was also unrest in the northwestern city of Rajshahi, where police beat BNP activists with batons as they marched through the streets, television pictures showed.
In the capital Dhaka, streets were empty, businesses and schools were closed as around 10,000 policemen were on patrol to prevent violence, Dhaka police spokesman Masud Ahmed told AFP.
Two small bombs were exploded in the city, but no one was injured.