Bomb blasts and arrests have marked an opposition-called general strike in Bangladesh in protest against a court order jailing 33 of the alliance's leaders.
No injuries were reported from the several explosions in Dhaka on Thursday. The United News of Bangladesh agency said at least 17 activists were arrested.
Schools and businesses were shut in the capital, with public life disrupted in other major areas during the shutdown.
A court on Wednesday denied bail to 33 opposition leaders charged with involvement in an arson attack during a strike last month.
The defendants include former cabinet ministers and the acting secretary-general of the Bangladesh Nationalist Party (BNP) led by the former prime minister, Khaleda Zia. It heads the 18-party opposition alliance.
Jebal Rahman Ghaani, BNP chairman, told Al Jazeera before the strike that "it is now quite clear a blatant inteference on the legal process is not acceptable to the people".
The opposition says the arson charge is politically motivated and the bail rejection is aimed at suppressing the opposition movement.
Political tensions have sharply escalated since Elias Ali, a BNP organising secretary, and his driver went missing on April 17 from a street in Dhaka.
The opposition blames the government and its security agencies for his disappearance, which they deny.
Ghaani, speaking to Al Jazeera, said "the government has been quite incompetent" in the handling of the case around Ali's disappearance.
Rights groups have recorded at least 22 disappearances this year and more than 50 since 2010, mostly of politicians.
Hillary Clinton, the US secretary of state, and officials from Amnesty International and Human Rights Watch have urged the government to investigate.
The opposition has set a June 10 ultimatum for the government to restore a caretaker government system to oversee the next national elections, due in 2014.
Sheikh Hasina Wajed's government scrapped the 15-year-old system last year in what the opposition says was part of a plan to rig the elections.
Police cordoned off the BNP headquarters on Thursday and scuffled with those who tried to enter.
"They had obstructed most of our offices from being attended by our political leaders and workers," Ghaani said of the police cordoning.
Witnesses say Khairul Kabir Khokon, education affairs secretary of the party, was arrested.
General strikes are common opposition tactics in Bangladesh used to embarrass the government.
Source: Al Jazeera and agencies