Students protesting a 2014 mass kidnapping directed a driverless freight truck to slide downhill towards a line of national guardsmen and police officers guarding a toll booth in Chilpancingo, southern Mexico on Friday.

Footage from news reports and videos on social media show an out-of-control large red truck driving dangerously close to the officers and crashing into an information stand, damaging a vehicle parked nearby.

Students earlier tried to seize the toll booths in an attempt to block the highway. Mexican media reported that they pelted officers with stones, bottle rockets, firecrackers, and Molotov cocktails. Police responded by firing volleys of tear gas.

El Financiero quoted law enforcement as saying 11 police officers and national guardsmen were injured during the standoff, and five students were detained. Other reports said that 20 students and 37 members of law enforcement were injured.

In 2014, 43 students from Raul Isidro Burgos Rural Teachers’ College, also known as Ayotzinapa Rural Teachers’ College, were abducted in Iguala and not seen since. The authorities eventually identified the remains of three victims.

The government and investigators said the students were taken by corrupt police officers and handed over to drug cartels.