Traffic queues stretched back for miles today as a bomb alert brought parts of the south east's main road artery to a standstill.

The M25 was thrown into chaos after the Dartford river crossing was completely shut off during the height of rush hour.

The bridge and tunnels were reopened at 10.20am - more than two hours after the road was closed.

Tens of thousands of motorists queued for miles as the motorway was closed after staff at the control centre were made aware of a suspicious package found at one of the toll booths.

Traffic queues on the northern side of the crossing, situated on the Essex-Kent border across the Thames, were stretching as far back as the M11 junction more than 15 miles away at 9.30am.

Kent Police had to call in bomb disposal experts who carried out a controlled explosion on the package at around 10am, although police would not confirm whether or not it was a bomb.

The crossing was closed to traffic between just after 8am and 10.20am causing major disruption for rush hour commuters.

Bosses at the crossing's control centre made the decision to completely close the river crossing after what they will only confirm as a major "security breach".

The barriers at the tolls closed immediately, blocking traffic travelling into Essex.

Traffic police from Tilbury and crossing patrol police were responsible for halting traffic as it approached the bridge to head into Kent.

As more and more cars joined the static queues from all directions, extra traffic police from Essex were called in to help.

A total closure has only happened a handful of times in the 35 years the crossing has been operating and it is not a decision staff take lightly.

With traffic building up at the rate of a mile every three minutes they knew total gridlock was a real possibility.

The knock on effect of the closure saw traffic on the A13 and the A127 grind to a halt as cars joined the queue.

Security alert - police officers halt traffic as both the Dartford Tunnel and QEII bridge are shut

Pictures: DAVE HENDERSON

Converted for the new archive on 19 November 2001. Some images and formatting may have been lost in the conversion.