Prime Minister Najib Abdul Razak has called on the authorities to take action under the Sedition Act against those spreading messages that can threaten racial harmony.

In view of this, he urged the Home Ministry as well as Communications and Multimedia Ministry to monitor the situation.

Najib also expressed regret that the violence which erupted outside Low Yat plaza last night had turned into a racial issue on social media.

He said police have taken action against the troublemakers.

"Everyone must stop spreading rumours and follow the police's statement.

"People shouldn't spread or create racial hatred on the internet or handphone apps," he said in his Chinese Facebook page called Ah Jib Gor.

Yesterday, several people, including three Chinese press journalists, were injured when an angry mob descended on the plaza over a dispute concerning a stolen handphone.

Police have since arrested 18 people and assured that the Bukit Bintang area is safe.