Security measures in the shape of semi-trailers, cranes and bollards made their presence felt in the centre of Sydney this week.
These are meant to protect pedestrians against car attacks following two such incidents in Melbourne that have shocked the country.
In the most recent one last week, a former Afghan refugee drove his four-wheel-drive vehicle into a crowd of people, injuring 19.
In Melbourne yesterday, police also tested a new loudspeaker system that issues warnings to the public in emergencies such as vehicle attacks, sieges and riots, or if there is an armed shooter.
