Muscat tweeted his thanks to police for "solving this important case of the cold-blooded murder of an Ivorian immigrant".

He said there was an ongoing investigation into "whether these are isolated, rogue individuals, or part of something wider".

"Words of hatred and division have no place in our society. It is a strong signal to all those who spread hate speech."

One of the arrested suspects admitted to targeting migrants "because they're black", The Times of Malta quoted a source close the investigation as saying.

Ivorian factory worker Lassana Cisse was killed in a drive-by shooting on April 6 that also wounded a Guinean and a Gambian, the paper said.

The arrested soldiers are suspects in another attack in which a teenager was wounded, the paper said.