Lancashire Police have confirmed the closure is between J9 (Rose Grove) and J11 (Burnley/Nelson).
Officers said they expect the road to be closed “for some time” and recommend drivers find alternative routes.
A police spokesperson said: “We want to update you and let you know that the M65 is currently closed in both directions from junction 9-11 due to a concern for welfare.
“We anticipate that the road will be closed for some time.
“In the meantime, we’d recommend looking for an alternative route and avoiding the area.
“We’ll keep tabs on what’s happening and we’ll update you here once the motorway is open.”
