Mass strikes across France against government plans to slash retirement pensions have halted most high-speed trains, canceled 30 percent of Air France domestic flights and shut 11 of 16 Paris Metro lines, as well as the Eiffel Tower.

Many schools were closed as teachers joined the strikes. Photographs of Thursday’s demonstrations show public workers carrying banners and flares as they march through France’s largest cities.

The strike, which is expected to continue until Monday, also paralyzed 90 percent of the country’s trains. The Eurostar train service, which connects London to Paris, Brussels and Amsterdam, announced significant cancellations.

Thursday’s strike is another test for President Emmanuel Macron who is pushing through France’s retirement system in the face of opposition from the country’s powerful trade unions. Thursday’s strike was the largest in a decade, outnumbering the “Yellow Vest” demonstrations.

The strike also forced France’s most iconic tourist spots to shut their doors. The Eiffel Tower and the Orsay museum did not open on Thursday due to staff shortages, while the Louvre, the Pompidou Centre and other museums said some of its exhibits would not be available for viewing.

According to local media, Yellow Vest protesters are blocking fuel depots in the Var department in the south and near the city of Orleans. As a result, on Thursday over 200 petrol stations had totally run out of fuel while over 400 were almost out of stock. The group has been demonstrating against Macron’s austerity measures for over a year.

Experts say that the strike, described as the largest of its kind in decades, could spell trouble for Macron. Building on ongoing demonstrations by the Yellow Vests, the strike could paralyze France and force Macron to rethink his planned reforms.

Macron has proposed making a single, points-based pension system which he said would be fairer to workers while also saving the state money. Labor unions oppose the move, arguing that the changes would require millions of people to work beyond the legal retirement age of 62 in order to receive their full pension.