Police in Bangladesh fired tear gas and rubber bullets to clear demonstrators trying to prevent authorities from evicting the leader of the opposition from a home she has occupied since 1982.
At least 50 people were injured and more than 20 demonstrators detained in the capital Dhaka, police said.
Police and witnesses said up to 4,000 protesters armed with sticks and stones set fire to vehicles and attacked officers near the headquarters of former prime minister Begum Khaleda Zia's Bangladesh Nationalist Party.
A similar number skirmished with officers close to Zia's house, and violence broke out in more than 20 towns across the country.
Around 50 people were injured in clashes with police in Serajganj, 94 miles northwest of Dhaka, as were dozens elsewhere, local television channels said.
"Sporadic violence is continuing. We are trying to disperse the activists," an officer told Reuters in Dhaka.
Clashes intensified as security forces cordoned off Khaleda's residence in the garrison as a deadline set by the High court on Friday neared for her to vacate the house.
Police later said the situation was under control but tense, while the opposition BNP called for a one-day strike.
"To protest the (eviction) order we have called for a countrywide dawn to dusk general strike on Sunday," Khondaker Delwar Hossain, secretary general of the BNP, told journalists.
It was not immediately clear whether the former prime minister had vacated the house. A defence ministry spokesman said authorities hoped Khaleda would leave to show compliance with the law and move into the house reserved for the leader of the opposition.
Khaleda's residence on a sprawling compound was leased to her by the government in 1982, after her husband, former president General Ziaur Rahman, was killed in an abortive coup.
The government of current Prime Minister Sheikh Hasina cancelled the lease last year to put up multi-storey buildings to accommodate families of army officers killed in a mutiny in a paramilitary unit headquarters in Dhaka.
Hasina was elected for the first time in 1996 and again in 2008 in an election held under an army-backed interim government.