The Lord Ayyappan devotees, hailing from Kancheepuram in Tamil Nadu, were heading towards the Sabarimala hill shrine of of Lord Ayyappa in Kerala when the incident happened at Chinnaru in the morning, they said.
Iron rods from the lorry pierced the front windshield of the van. All the 18 devotees in the van were injured. Eleven of them, including two seriously injured, had been hospitalised while the others were treated as out patients, police said.
The seriously injured has been shifted to the government hospital in neighbouring Tiruchirappalli while others were undergoing treatment at the local government hospital, they said.
A large number of devotees from southern states, especially Tamil Nadu, undertake the pilgrimage to the Sabarimala temple, which opens tomorrow for the two-month long annual festival that would culminate with the 'Mahara Jyothi', celestial star, in mid January.