Prime Minister Joseph Muscat said he was "flabbergasted" when he heard Daphne Caruana Galizia was killed in a car bomb.

The 53-year-old journalist died in an explosion shortly after she left her home in Bidnija, near Mosta, on Monday.

She was known for her blog accusing top politicians of corruption.

Her son, Matthew, has denounced what he called the country's "mafia state".