LONDON (Reuters) - British police sealed off busy road crossings across the River Thames near London on Friday, causing hours of chaos for thousands of rush-hour motorists after the discovery of a suspicious item prompted a major security alert.
The bridge and two tunnels which make up the Dartford Crossing carrying traffic on the M25 London orbital motorway across the river, were closed following reports of a pedestrian "behaving unusually" and the discovery of the unspecified item.
Bomb disposal experts were called to the scene but some six hours after the closure, police said inquiries had concluded that it posed no threat. However, the arrested man remained in custody, Kent Police said in a statement.
"He came back towards the cars, he went across into the lane next to me, tried to get in the car next to me, he was shouting something," motorist Graeme Brouder, 36, was quoted as saying by the BBC.
"He was shouting at that car, tried to get in that car, ran past mine, tried my door handle, and then ran down the lane behind me and he was just shouting at everyone. He was running around, he was trying to get in everybody's cars."
In a second operation linked to the Dartford incident, police said they had stopped a long-distance bus near the port of Dover, leading to the closure of the main A20 road.
No items were found and no arrests made, police said, and the road was later reopened.
The Dartford Crossing, about 20 miles east of London, carries some 165,000 vehicles on its busiest days and the six-hour closure of the road in both directions caused long lines of traffic with cargo trucks stuck on the 1.8 mile bridge.
"Kent Police would like to thank motorists for their patience and support during what must have been a very frustrating wait," the police said.
(Reporting by Michael Holden; Editing by Andrew Roche and Eric Walsh)