Sheets cover the bodies of cyclists struck by a speeding car, partially seen at right, in southern Italy on Sunday morning. Eight cyclists were killed. ((Adriana Sapone/Associated Press))

A speeding car plowed head-on into a group of cyclists in southern Italy on Sunday morning, killing eight of them, officials said. The driver had been smoking marijuana, police alleged.

Bent, mangled bikes were strewn about the scene, and the sheet-draped corpses dotted the two-lane road near Lamezia Terme, in the Calabrian "toe" of boot-shaped Italy where the accident occurred.

In addition to the eight cyclists killed, four people were injured, said Gianluca Gioia, a spokesman for ANAS, the agency that runs Italy's state roads and highways. Police confirmed the toll.

The ANSA news agency said the driver, who was slightly injured, was placed under arrest. A police spokesman who declined to give his name said the man, a Moroccan national, had tested positive for marijuana.

A preliminary investigation showed the speeding car ran head-on into the cyclists, who were riding in the opposite direction on state road 18, according to the highway authority.

ANSA said the driver was trying to pass another car when he hit the group. Visibility and driving conditions were good at the time, reports said.

The road was closed by authorities.

It is common in Italy to see groups of amateur cyclists taking to small state roads on weekends. ANSA said the group hit Sunday was affiliated with a local Lamezia Terme gym.