Tens of thousands of opposition supporters have rallied in Bangladesh’s capital to demand the government of Prime Minister Sheikh Hasina resign and install a caretaker before next general elections expected to be held in early 2024.

The supporters of the Bangladesh Nationalist Party (BNP), headed by former prime minister Khaleda Zia, reached the protest venue in Dhaka overnight amid tight security while home minister Asaduzzaman Khan warned over fears of violence at the rally.

Ms Hasina and her ruling Awami League party, which returned to power in 2018 for the third consecutive time, have repeatedly ruled out the opposition’s demand, saying a caretaker government goes against the spirit of the country’s constitution.

The venue at Golapbagh in Dhaka was filled up by Saturday morning and the crowd spilled out into streets chanting slogans such as “Down with Hasina” and “We want a fair election”.

Saturday’s rally was the 10th from the main opposition party after it announced in September it would hold protests in 10 big cities across the country.

All the previous rallies outside Dhaka drew huge crowds despite challenges including what the party said were politically motivated transport strikes and intimidation by security agencies and the ruling party. Police and the ruling party denied such allegations.

The rally in Dhaka was held during heightened tension after police stormed the party headquarters following clashes between officers and opposition supporters on Wednesday, leaving at least one dead and 50 injured.

Police arrested more than 400 opposition activists.

On Friday, detectives raided homes of two senior party leaders, including secretary general Mirza Fakhrul Islam Alamgir. Both were denied bail.

Zahiruddin Swapan, a former two-time opposition legislator and party spokesman, told the Associated Press that by Saturday afternoon about 1.5 million opposition supporters had joined the rally.

“We want a free and fair election. To facilitate that, this repressive government must go, parliament must be dissolved, and a new election commission should be installed,” he said. “They came to power through vote rigging and intimidation.”

Faruk Hossain, a spokesman for Dhaka Metropolitan Police, told AP that the venue has a capacity of 30,000 people and if adjacent streets were included, the rally could not have drawn more than 60,000 people.

Witnesses said up to 100,000 opposition activists joined the rally.

An election-time caretaker government system was introduced in the constitution in 1996 to oversee national elections, but it was nullified in 2011 under Ms Hasina through a constitutional amendment after the Supreme Court ruled the system was contradictory to the constitution.

The BNP boycotted the election in 2014, and the results of the vote in 2018 were disputed because of allegations of vote rigging by the ruling party, which won with an overwhelming majority.

On Saturday, seven BNP legislators at the rally announced their resignations from parliament.

Fifteen western embassies issued a joint statement on Tuesday calling for the government to allow free expression, peaceful assembly and fair elections, with the UN making a similar declaration a day later.

Bangladeshi politics has been polarised with Ms Hasina and Ms Zia being the most influential rivals. Although the country is a parliamentary democracy, it has a violent history of coups and counter coups.