Italy made Covid-19 health passes mandatory for all workers from Friday in a test case for Europe, with the measure being applied mostly peacefully across the country despite scattered protests.

Prime Minister Mario Draghi's cabinet approved the rule — one of the world's strictest anti-Covid measures — in September, making it obligatory from Oct 15 for all workers either to show proof of vaccination, a negative test or recent recovery from infection.

Under the rule, effective until year-end, workers without the so-called "Green Pass" will be suspended without pay and face a fine of up to 1,500 euros ($1,730) if they try to work on regardless, Reuters reports.

The largest demonstrations were at the major northeastern port of Trieste, where labour groups had threatened to block operations and around 6,000 protesters, some chanting and carrying flares, gathered outside the gates.