Sri Lanka was braced for more unrest after newly appointed president, Ranil Wickremesinghe, vowed to crack down on the protests that toppled his predecessor, condemning them as “against the law”.

Speaking after being MPs picked him as successor to Gotabaya Rajapaksa, Wickremesinghe made it clear he would not tolerate those he perceived to be stirring up violence.

“If you try to topple the government, occupy the president’s office and the prime minister’s office, that is not democracy; it is against the law,” he said.

“We will deal with them firmly according to the law. We will not allow a minority of protesters to suppress the aspirations of the silent majority clamouring for a change in the political system.”

In recent days, Wickremesinghe, who declared a state of emergency this week, had made statements calling protesters “fascists” and indicating he would not be afraid to crack down on the demonstrations.

Less than an hour after he was declared president on Wednesday, a court order was issued prohibiting anyone from congregating within a 50-metre radius of a statue that stands at Galle Face in Colombo, where protesters spurred by the country’s economic collapse have been camped out for months.

However, people defied the order and dozens gathered on the steps of the president’s offices, which are still occupied by the protest movement, to shout rallying cries of “deal Ranil” – a reference to Wickremesinghe’s reputation as a scheming politician – as well as “Ranil bank robber”, referring to a bank bond scam he was implicated in. Hundreds of police and military stood on the periphery but did not interfere in the rally.

Wickremesinghe has been prime minister six times and is close to the Rajapaksa family. Protesters fear that he will protect the Rajapaksas from being held accountable, as he has been accused of doing in the past, and would not instigate the constitutional change being demanded by the protest movement, including an end to the system of executive presidency.