A Bangladesh opposition group has called for a four-day national blockade in a bid to force Prime Minister Sheikh Hasina to step down ahead of a general election on January 5.

During a press conference on Thursday, Bangladesh National Party (BNP) committee member, Nazrul Islam Khan, announced the blockade, the fifth since protests began in October, which will take effect at 6am on Saturday.

Previous blockades have targeted transport across the country, leading to an estimated $40b loss of revenue for Bangladesh after rail and road shipments were halted and industries like the garment business losing western custom.

Also on Thursday, Bangladesh security forces arrested more than 100 protesters as they launched an offensive on the opposition ahead of the controversial general election.

Officials said the protesters were detained in joint operations by the police, the elite Rapid Action Battalion (RAB) and paramilitary border guards.

The "joint forces" arrested 118 people, mostly activists from the main opposition BNP and its key ally Jamaat-e-Islami, in five districts where police had earlier clashed with demonstrators.

Election boycott

Both groups have said they will boycott the polls if the election goes ahead while Hasina is still in office.

The BNP, Jamaat and their smaller allies have been staging protests since late October to try to force Hasina to step down so that a neutral caretaker government can oversee the election.

She refuses to accept the arrangement, which was in place during previous national polls.

The BNP has refused to field candidates for the January election, saying the vote under Hasina will be rigged, an accusation the premier rejects.

Jamaat, the country's largest Islamist party which has been barred from contesting the polls, is also furious with the government after one of its leaders, Abdul Quader Mollah, was executed last week for crimes during the 1971 independence war.

Source: Al Jazeera and agencies