Kerala Chief Minister Oommen Chandy was injured after his car was stoned by suspected CPM activists here, a party leader said.

Chandy was arriving to attend the annual athletics meet of Kerala Police.

Speaking to reporters, party general secretary T.Siddiq said that he was travelling with the chief minister in his car when the attack occurred.

"...Stones came from both sides and I immediately threw my hands around him to protect him and a stone hit my hand. The glass pieces came flying and hit him on the forehead and injured him," he said.

State party chief Ramesh Chennithala said they suspect there was a conspiracy behind the attack and demanded a probe.

"We have called for a statewide protest today (Sunday) night against this ghastly attack. There is every reason to suspect that this was a pre-planned attack and was perhaps done with the knowledge of the Left Democratic Front leaders... a probe has to be conducted," he told reporters.

Kannur district has always been the stronghold of the CPM and top party leaders, including state secretary Pinnarayi Vijayan and politburo member Kodiyeri Balakrishnan, hail from there.