The organiser of the Himpunan Hijau gathering said they will stay put in Dataran Merdeka until 9am, Monday.

Himpunan Hijau’s chairman Wong Tack said they would remain outside the square and want the authorities to meet them.

"We want the minister responsible to come here and meet us. We shall wait until 9am. We have come this far from Kuantan, so we just want the minister to come here from Parliament which is only three minutes from here,” said Wong.

Wong however said the group however will not march to Parliament as originally planned.

The huge crowd of about 10,000 protestors who are against the setting up of the Lynas Advanced Materials Plant in Gebeng, Kuantan gathered outside Dataran Merdeka on Sunday after marching about 300 kilometres from Kuantan.

However, more than three quarters of the crowd started to disperse by 6.30pm and there were no reports of unwanted incidents.

Police said they will continue to monitor the Himpunan Hijau protestors at Dataran Merdeka and surround areas despite being told that they had clearly violated Section 9 (1) of the Peaceful Assembly Act 2012.

Dang Wangi OCPD, ACP Zainuddin Ahmad said the organiser did not issue any notice to the police of their gathering as required by the new Act.

“I have not received any notice because under Section 9 (1) the organiser is required to issue a notice 10 days prior to the gathering. So no notices were sent to me,” he said today.

He also said that the organiser had committed an offence under Section 9 (5) of the Peaceful Assembly Act 2012.

When asked whether the police would take any action should the protesters fail to disperse, Zainuddin said: “We will monitor them.”

Zainuddin said the organiser has the legal responsibility to present a notice to the police chief as stipulated under Section 9 (1) of the Peaceful Assembly Act 2012.

“Failure to do so may cause the organiser to be penalised under Section 9 (5) of the Peaceful Assembly Act 2012."

A Kuala Lumpur City Hall enforcement officer, Nasaruddin Daharun also reminded the organiser and protesters that Dataran Merdeka is under City Hall's jurisdiction and it has every reason to stop anyone from being in that area.

He also told that the square is undergoing an upgrade process and therefore any kind of gathering is strictly prohibited.

The police and City Hall had also set up two layers of barricades to prevent the protesters from breaching the gate like what happened in the recent Bersih 3.0 gathering.