Police in Bangladesh’s capital on Saturday clashed with supporters of the main opposition party, which said many of its activists were injured during anti-government protests in parts of Dhaka.

The Bangladesh Nationalist Party (BNP), headed by former Prime Minister Khaleda Zia, demanded the resignation of Prime Minister Sheikh Hasina and the transfer of power to a non-party caretaker government until the next general election, which is expected to be held by early January.

The BNP and its allies accuse Hasina of vote rigging in 2018 and the party has been protesting over who should oversee the next general election.

On Saturday, hundreds of workers of Zia’s party attempted to block several entry points to Dhaka while police used tear gas and batons to disperse them. The BNP workers retaliated by throwing pieces of brick and attacking police vehicles with sticks, police said.

On Friday, the BNP announced the sit-in protest at all the entrances of Dhaka, and supporters of the ruling Awami League party also took to the streets.

Faruk Hossain, a spokesman of the Dhaka Metropolitan Police, said officers arrested at least 90 opposition workers during the five-hour protest in parts of the city and 20 police were injured in clashes with the protesters.

Zia’s party said later in the evening that more than 100 opposition workers were injured. The party also said at least 124 of its members were arrested by police.

Police said two senior leaders were detained briefly, but were later released.

Hasina hopes to return to power for a fourth consecutive term and says the election should be held under her government’s supervision as specified in the constitution.

But Zia’s party and its allies accuse Hasina of vote rigging in 2018 and say she must step down to allow the installation of a non-party caretaker government to ensure a free and fair vote.

The United States, the European Union and the United Nations have urged the sides to demonstrate restraint and work towards holding a credible election.