Western governments – along with the United Nations – have expressed concerns over the political climate in Bangladesh, one of the fastest growing economies in Asia.
The country was long aligned with the United States but in recent years, Hasina has courted deeper ties with China, with Beijing bankrolling some of her multi-billion-dollar infrastructure projects.
The opposition has been holding protests around the country demanding Hasina resign and call an election under a caretaker government – which she has rejected outright.
A BNP official claimed that some 200,000 people had joined Saturday’s rally by mid-morning.
“Our main demand is Sheikh Hasina resign and parliament is dissolved and let a neutral caretaker government step in to hold a free and fair election,” spokesman Zahiruddin Swapan told AFP.
Dhaka Metropolitan Police spokesman Faruq Ahmed dismissed the figures, saying the venue could not hold more than 30,000 people.