Protesters in Sri Lanka who brought down the previous government announced they were dismantling their main demonstration site near the president's office on Wednesday in the wake of a crackdown against their leaders.

The group led by university students and leftist parties said they were clearing out their tents along the Galle Face seafront promenade in the capital.

A spokesman said they had also withdrawn four court challenges against a police order for them to vacate the area that claimed their tents were a hindrance to nearby hotels.

Activists were seen taking down their tents and removing other structures they had put up supporting their struggle against the administration.

The demonstrations began on April 9 as a protest against shortages of essentials such as fuel, food and medicines in Sri Lanka's worst ever economic crisis.

They peaked when tens of thousands poured into Colombo and overran Gotabaya Rajapaksa's presidential palace on July 9, forcing him to flee and eventually resign.

Days after Rajapaksa fled to Singapore and announced his resignation, troops evicted protesters occupying the palace as well as the home and office of the prime minister.

Security forces were accused of using excessive force to evict the demonstrators, with more than 80 people suffering injuries that required hospitalisation.

Since then, dozens of activists have been arrested on charges of damaging state property.

A top trade union leader, Joseph Stalin, was released on bail Monday following international criticism over his arrest last week on a charge of causing $90 worth of damage.

Rajapaksa's successor, Ranil Wickremesinghe, has drawn a distinction between "protesters" and "rioters" and vowed tough action against "any troublemakers".

Soon after protesters overran the palace, there were social media posts of them frolicking in the pool and bouncing on four-poster beds inside the sprawling compound.

But protesters also turned over to authorities around 17.5 million rupees ($46,000) in cash found in one of the rooms.