British Defence chiefs have apologised to Spanish authorities after a detachment of British commandos accidentally "invaded" Spain.
The 20 Royal Marines, based near Arbroath, roared up a beach in their amphibious landing craft and leapt ashore brandishing assault rifles and mortars.
Bemused Spanish fishermen in the town of La Linea de la Concepcion watched as 45 Commando began deploying 'tactically' in the sand.
In the end, two local policemen took it upon themselves to point out to the marines that Gibraltar - the intended target of their seaborne landing exercise - was actually a little further on down the coast.
There was apparently a brief flurry of apologies from the red-faced commandos before the men jumped back into their craft and motored further south.
The gaffe comes at a time of delicate negotiations over the future of Gibraltar, which was taken by Britain in 1704. Nine years later The Rock was ceded to Britain for ever under the Treaty of Utrecht.
A Ministry of Defence spokesman said the "regrettable" incident happened during an exercise by Royal Marines travelling on HMS Ocean, the Royal Navy's helicopter and commando carrier.
"In the course of the exercise, a landing craft meant to land in Gibraltar, but made it a few yards down the beach, on the Spanish side," he said.
"There is much embarrassment, the error is regretted and lessons have been learned. They were informed of their error by local policemen and spent only about five minutes on the beach."
He said: "We were not trying to take Spain and have no plans to do so."