Two suspects were arrested for allegedly throwing stones at a public meeting in Ratmalana which was attended by Opposition Leader Sajith Premadasa yesterday, police said.
They said the suspects were arrested last night following the incident.
The attack took place minutes after MP Premadasa began his speech. Bodyguards surrounded him as stones were being hurled to the stage.
Police said the two suspects aged 40 and 21 are alleged drug addicts from the Mount Lavinia area.
The suspects are to be produced before the Mount Lavinia Magistrate today.