(Reuters) - Thieves apparently trailed a van from a jewelry trade show in Illinois for several hours, then smashed the back windows early on Monday at a rest stop in southern Minnesota and made off with about $500,000 of loose diamonds and jewelry, authorities said.
The owner of a precious stones and metals business was with six employees when they stopped to use the bathroom at the rest stop along westbound Interstate 90 near Eyota, Minnesota, said Captain Scott Behrns from the Olmsted County Sheriff's Office.
Behrns said two employees were in the van when a second van pulled up suddenly behind them and four men dressed in black with hoodies pulled over their heads smashed the windows and took three or four cases.
An employee in the driver's seat at the time of the robbery put the van in reverse and smashed into the suspect's vehicle, causing extensive damage, Behrns said. No one was injured and no weapons were seen, he said.
"It was probably done in 90 seconds or less," Behrns said, adding that the speed suggested that the robbery was planned and the rest stop a location of opportunity.
Behrns said the damaged van was found abandoned along I-90 about a mile from the rest stop and the suspects may have gotten a ride from second vehicle, which may have been part of the robbery plan.
Behrns said the items stolen included diamonds, gold and silver necklaces, pendants and chains. Some inventory was left in the dealer's van, he said.
Behrns did not identify the names of the robbery victims or where they were from. The Federal Bureau of Investigation and Illinois authorities have been contacted, he said.
(Reporting by David Bailey in Minneapolis; Editing by Eric Walsh)