WASHINGTON - A charter bus crashed into a tractor-trailer early Sunday morning in US state of Virginia, leaving 19 people hospitalized, the authorities said.

"Heavy fog and icy road conditions are to blame," Virginia State Police spokeswoman Corrine Geller told local media.

The driver of a tractor-trailer lost control, and the semi truck filled with mail overturned, state police said. A nearby charter bus wasn't able to avoid the overturned semi and struck it, according to a CNN report.

No fatalities were reported. The injuries of those hospitalized range from serious to minor, said the report.

"The impact of the crash split the tractor-trailer in half," Geller said. "The bus ran off the right side of the highway and came to rest against the guardrail."

The crash happened around 4:30 am local time on a highway about 25 miles (40 kilometers ) west of Charlottesville, Virginia.