Update | Malaysian officials threaten action against anti-Najib protesters; ruling party vows '1 million supporters' will stage rival rally

The Malaysian government threatened to take action against the organisers of a massive protest rally demanding the prime minister’s resignation over a corruption scandal, which saw thousands of people take over the streets of central Kuala Lumpur.

The two-day rally, one of Malaysia’s largest in years, has been mostly incident-free even though police declared it illegal, blocked the organisers’ website and banned their official bright yellow T-shirt and logo.

Deputy Prime Minister Zahid Hamidi, who also is home minister in charge of domestic security, warned that organisers could face possible charges under assembly, sedition and other laws.

“We also follow every word they say, we know the actions taken by them,” he was quoted saying by state media.

"They must face the consequences if they dare to break the law," he said, according to a New Straits Times online report.