The BNP said the cases were politically motivated, aimed at crushing the only opposition party in the country that can offer a realistic challenge to Prime Minister Sheikh Hasina’s 15-year rule.

Bangladesh is set to hold a general election on Jan 7, with Hasina eyeing her fourth consecutive term in power.

Many were convicted on historic charges over protest violence, with convictions ranging from two-and-a-half to seven years.

Monir uz Zaman, a prosecutor, said 75 BNP activists were sentenced in a Dhaka court to two-and-a-half years on charges of violence and arson during political turmoil in 2013.

Zaman said 72 of the 75 were “absconding” and were now wanted fugitives.

Taposh Kumar Paul, another prosecutor, told AFP another Dhaka court sentenced 12 BNP activists to seven years in jail for violence in 2015.

Nazrul Islam, a defence lawyer, said 11 more BNP members were sentenced to seven years in jail yesterday for violence during political clashes in 2013.

Several of those convicts were also sentenced in absentia.

Islam said cases had been “conducted in a hurry”.

Kayser Kamal, BNP’s legal chief, said at least 400 BNP senior officials and activists have been sentenced in recent days.

They included former lawmakers, youth and student leaders, and those who had hoped to contest elections.

“These cases are staged, baseless, and politically motivated,” he told AFP. “Trials of these cases started all of a sudden just a few weeks before the national election”.

The BNP has staged a series of major rallies and marches in a bid to force Hasina to quit power and let a neutral government run the polls.

But since late last month, the police have cracked down on the opposition, arresting almost the entire top leadership of the BNP and arresting thousands of its activists and supporters.

Hasina has overseen impressive economic growth during her 15 years in power, but there has been international alarm over her increasingly authoritarian rule and thousands of extrajudicial killings.