An important shipping strait between two Danish islands was closed for several hours on Thursday after a missile malfunction on a navy frigate, the military said.

The malfunction happened during a missile test on the Niels Juel frigate in the port of Korsor, west of the capital Copenhagen, which created the risk of a missile launch.

"The problem happened during a compulsory test where the launcher had been activated" and could not be deactivated for several hours, the Danish Defence Command explained in a statement.

As long as the launcher was not deactivated, there was "a risk that the missile would be fired and would travel several kilometres", the military said, adding however that there was no risk of the missile exploding.

The Great Belt shipping lane, which separates the islands of Zealand and Funen, and air traffic over it were closed between mid-afternoon and 8:00pm (1800 GMT).

Road traffic on the bridge between the two islands was not suspended, however.

The incident happened a day after Defence Minister Troels Lund Poulsen sacked Chief of Defence Flemming Lentfer after having "lost confidence" in him.

Poulsen said he had not been informed about a malfunction on a Danish frigate sent to the Red Sea to protect commercial shipping against attacks by Yemeni Houthi rebels.