While CPI(M) alleged that BJP and RSS were behind the incident yesterday, the saffron party rebutted the charge, saying the Left leadership was trying to spread "fake news" and create tension in the district.
Police said no untoward incident was reported from any part of the district and the situation is now under control.
Patrolling and searches have been intensified in the district, which has witnessed frequent clashes between BJP-RSS and CPI(M) workers after the May 16 Assembly polls last year that saw LDF coming to power.
In retaliation, BJP offices at Nadapuram and Vadakara in neighbouring Kozhikode district were vandalised, allegedly by CPI(M) activists, last night soon after the incident.
More From This Section
To condemn the attack on its party offices, BJP observed a dawn-to-dusk hartal in the area today.
A local BJP panchayat president was allegedly manhandled in a scuffle between the CPI(M) and BJP workers during the hartal, police said.
CPI(M) veteran V S Achuthanandan alleged that the BJP and RSS, "under the shadow of the Narendra Modi government", was repeatedly trying to create tension through provocation.
"All who value democratic principles should come forward and be vigilant against this attitude of Sangh Parivar forces," the former Chief Minister said, adding there should not be any lapse on the part of police to bring to book those responsible.
Denying the allegations, BJP state president Kummanam Rajasekharan said CPI(M) was unleashing large-scale violence in the district by spreading "fake news" of bomb hurling near the venue of Balakrishnan's meeting.
Opposition leader Ramesh Chennithala also condemned the bomb hurling incident and appealed to both parties to eschew violence.
On January 18, a 53-year-old BJP worker was stabbed to death at Andaloor in Dharmadam, the constituency of Chief Minister Pinarayi Vijayan. Six CPI(M) workers were arrested in this connection.