Provincial police are remaining tight-lipped about an investigation that kept a service centre off eastbound Highway 401 near Woodstock closed for much of the morning on Monday.

Oxford OPP shutdown the Woodstock OnRoute around 3:30 a.m. They released no details about the investigation, what it pertained to, or if anyone was hurt.

In an update issued around 8:30 a.m., police reassured there was no threat to public safety. The OnRoute reopened about half an hour later.

The investigation is ongoing, police said.