A controlled explosion is due to be carried out on a suspicious package found in Rotherham.
The package was found in the car park of a training centre on Temple Road, off Sheffield Road, close to the Templeborough pub.
There is an electricity substation close by, which serves the Tat Steel plant on Sheffield Road.
Police officers called to the scene have sealed off the area and evacuated some local businesses.
Hundreds of Kier workers at a conference at Magna were among those ushered away from the area.
Other firms have been advised not to allow workers to leave their buildings until the explosion has been carried out.
A controlled explosion is due to be carried out by an army bomb squad from Chester.
Phil Coley, director of Duo Call Communications, which is close to the police cordon, said: "They are taking this extremely seriously.
"I suppose it could be a bag that somebody has left by mistake, but they have to take it seriously.
"They evacuated our building because of how close we are to where the package has been found.
"There were two or three police cars at first but then loads arrived and they were turning cars away from the area."
A South Yorkshire Police spokeswoman said: "A cordon is currently in place on Temple Road, Rotherham, after police received reports of a possible suspicious package at around 9am this morning.
"The site and surrounding areas have been secured and police are currently liaising with the explosive ordinance disposal unit.
"Sheffield Road and Temple Road have both been closed."