The Danish military says a missile failure on a navy ship has triggered the closure of airspace and shipping lanes near a major shipping strait off the Danish coast.
The National Maritime Authority issued a warning for ships to avoid part of the Great Belt strait due to a risk of "falling missile fragments".
Ships have been asked to drop anchor if necessary.
A naval exercise began in the area last March and is due to end on Friday.
In a statement, the Danish military said the problem with the missile occurred "during a mandatory test where the missile launcher is activated and cannot be deactivated."
"Until the missile launcher is deactivated, there is a risk that the missile can fire and fly a few kilometres away," the military added.
The warning covered an area south-west of the town of Korsor, some 4km (2.5 miles) south of the Great Belt bridge, which crosses the strait.
The bridge remained open to traffic, its operator said.
The Norwegian Defence Ministry said the missile contained 150kg of explosives, adding that it was not armed and would not detonate if it crashed into the sea.
