Their condition is not yet known.
The accident happened at around 1.15pm in Rue d’Argens Street.
The incident happened at around 11.30am.
A 27-year-old motorcyclist was grievously injured in a collision that took place in Naxxar on Friday.
A 32-year-old woman was grievously injured when the motorcycle she was riding pillion in was involved in a collision in Mdina Road, Żebbuġ.
Germany increased security at some carnival processions on Tuesday after a local man ploughed his car into a parade in the western German town of Volkmarsen, injuring 61 people, including 20 children.