Emdad Hossain, a doctor at the emergency department of Dhaka Medical College hospital, told AFP that police handed over the body of the man who appeared to have been run over by a vehicle.
At least 10 other people were treated at the hospital, although their conditions were not serious, he said.
The clashes, shown by the private Ntv news channel, took place on Monday, the second day of a nationwide transport blockade organised by opposition parties to force the resignation of an election official accused of trying to rig national polls in January.
Awami League, the main opposition party, and its allies have said that MA Aziz, the chief election commissioner, tried to unfairly influence elections, being organised by the country's interim government, in favour of the outgoing Bangladesh Nationalist Party-led (BNP) administration.
Thousands of opposition supporters chanting "Sack Aziz and save the country" staged demonstrations and blocked roads nationwide, police said.
A mob enforcing the blockade smashed at least 11 buses at Savar, 40km west of Dhaka, the private UNB news agency reported.
Thousands of protesters blocked
The roads were empty and many offices and schools remained closed in Dhaka and other major cities. Deliveries to and from the country's main port in southeastern Chittagong also remained suspended, and rail services were disrupted, officials said.
Meanwhile, the caretaker government has said it is working to try to end the deadlock.
Fake voter list
The opposition has accused Aziz's commission of drawing up a list that contains 10 million fake voters, and that fair elections cannot be held with him in place.
It has threatened to boycott the polls unless a string of demands, including his sacking, are met.
At least 25 people died in four days of clashes between rival party activists when the BNP-led government's five-year mandate expired on October 27.
The clashes began when the opposition staged mass protests that led KM Hasan, a former Supreme Court judge, to decline to continue as head of a caretaker government in late October. The opposition accused him of being politically biased in favour of the BNP.
After talks between the BNP and the Awami League to find a compromise candidate broke down amid spiralling violence, Iajuddin Ahmed, the president, installed himself as head of the temporary administration on October 29.
The Awami League later called off its protests, saying it wanted to give the president time to show he could be non-partisan.
On Saturday, however, it announced a resumption of protests and an indefinite nationwide road, rail and river blockade, and accused the president of failing to demonstrate his neutrality by not sacking Aziz.