Pimentel hurt his right hand but was otherwise out of danger.
Lawyer Francis Navarette, a legal staffer of the senator, said Pimentels Pajero was northbound when a pog-pog (handtractor-drawn cart) it was tailing suddenly crossed the other side of the national highway in Barangay Bakal II, Talavera town.
The senators driver tried to avoid the pog-pog but instead slammed onto the parked truck.
Some of the carts occupants also sustained slight injuries.
Navarette said the senator even talked with the occupants and told them to go to the hospital for treatment. He then proceeded to the Central Luzon State University here where he was one of the resource persons in a forum on genetically modified organisms.
"The funny thing was that the accident happened even when the Pajero was cruising at a speed of only 20 kilometers per hour," Navarette said.
He said they were trying to locate the families of the pog-pogs occupants to extend financial assistance to them but there were no reports of any vehicular accident in either the local hospital or police station.
"The occupants of the pog-pog perhaps no longer went to the hospital," he said.