No police in uniforms, no Federal Reserve Unit (FRU) and no water cannons were seen during the illegal opposition rally held by the opposition at the Kelana Jaya Stadium here Wednesday night.

It was also attended by a number of opposition leaders.

Police have classified it as an illegal rally because the organisers failed to give 10 days advance notice on holding it as required under the Peaceful Assembly Act 2012.

Selangor police chief Datuk Tun Hisan Tun Hamzah said police would take action against the organisers for failing to give sufficient notice under Section 9(5) of the same act.

"We are also studying the speeches made at the rally to see if there were elements of sedition under Section 4(1) of the Sedition Act 1948," he told Bernama via the short-messaging service.

The rally which was attended by thousands caused a massive traffic gridlock in the area around the stadium which lasted for hours.