SOUTHAMPTON dock chiefs have warned residents 'not to be alarmed' as they prepare to run an emergency drill.

The drill will simulate a ferry colliding with a tanker just off Fawley Oil Refinery.

Oranges will be thrown into the sea to represent the oil that would be in the water.

Ahead of the multi-agency drill, which will involve crews from Hampshire Fire and Rescue, the port tweeted: "We are conducting an oil spill emergency response exercise this morning so don't be alarmed if you see some unusual activity."

Captain Phil Buckley, Harbour Master, said: "The purpose is to test our contingency plan.

"The likelyhood of something like this happening is very small, but if it did happen the concequences can be significant.

"We get to work together with a number of operators in the region and the emergency services and we get to know each other in case it were to happen."

He added: "We are very proud of our environment record.

"It has been a couple of years since we last had a drill.

"We need to make sure the drill is demanding enough, but not too much so we don't need a bigger response."

Southampton water sees 160,000 vessels pass through each year.