SIBLEY, Iowa (AP) — Thick black smoke billowed into the air Sunday after a train derailed in northwest Iowa, prompting authorities to evacuate part of a small, nearby town.

The fiery derailment happened around 2 p.m. Sunday on the southwest edge of Sibley, which is a town of about 3,000 people roughly 200 miles (321.87 kilometers) northwest of Des Moines. There were no immediate reports of injuries related to the derailment.

Photos and video of the derailment posted online Sunday show dozens of train cars piled up along the tracks with flames and a large plume of smoke coming from one end of the pile of cars. Local media reports say authorities evacuated an area within 5 miles (8.05 kilometers) of the derailment.

Union Pacific spokeswoman Robynn Tysver said about 47 railcars came off the tracks during the derailment, but the train crew was not injured. She said the railroad is working with local authorities.

Tysver said the cause of the derailment is under investigation.

Sibley Fire Chief Ken Huls told KIWA radio the train was hauling fertilizer and ammonium nitrate.

Nate Minten of Sibley told the Des Moines Register that smoke was still visible around 4:30 p.m. Sunday from his mother's home.

“I could see smoke filling up a couple hundred feet at least,” said Minten who posted aerial drone video of the derailment online, “We didn’t hear any bangs or anything.”

An emergency text message Minten received about the derailment said the western end of Sibley west of Second Avenue was being evacuated.