Paris
CNN
 — 

French transport networks, oil refineries and schools were hit by widespread disruption Thursday as workers staged a national strike to protest an increase in the retirement age that was pushed through parliament without a vote.

Though sporadic demonstrations had popped up in Paris and other cities after the French government forced the bill through last week, Thursday marked the first day of coordinated action since then. It is the ninth day of strikes since the bill was introduced in January.

Only two out of 14 metro lines in Paris were operating a normal service. RER train services, which run in the city and its suburbs, were severely reduced and only half of high-speed TGV trains were working. The nationwide strike has also affected air traffic, with 30% of flights impacted at Paris Orly airport.

Unionized workers blockaded a major oil refinery in Normandy and another one in Fos-sur-Mer in the south of France, according to a government spokesperson.

“We are intervening in a targeted manner to unblock oil storage tanks that are blocked by demonstrators,” the minister of energy transition, Agnès Pannier-Runacherin, said in a statement.

“If the strike is a fundamental constitutional right, blockading is not one… The police is mobilized in difficult conditions and has my full support.”

The government renewed its requisition order requiring workers to go back to work at the two blockaded refineries, the government spokesperson said.

The government’s plan to raise the retirement age for most workers by two years was opposed by huge numbers of people. But despite protests that drew more than a million people onto streets across the country, President Emmanuel Macron’s government did not back down. It rammed the legislation through the French National Assembly last week using a constitutional clause that allows the government to bypass a vote.

The country’s generous pension system and early retirement have been a point of pride since they were enacted after World War II. Under the new law, the retirement age for most workers will be 64, still one of the lowest in the industrialized world.

As a result of the refinery strikes, kerosene stocks at Charles De Gaulle airport, which serves Paris, were “under pressure,” and those at Orly airport were being monitored, according to the civil aviation authority.

Earlier in the day, around 70 protesters blocked terminal one at Charles de Gaulle airport, an airport spokesperson told CNN.

About 20% of teachers in public education also took part in the strikes, according to France’s education ministry.

Macron and his government have defended the retirement reform as necessary to keep the pension system funded. Taxes on current workers pay for the benefits of retirees, and as people live longer — and more baby boomers retire — the system would otherwise eventually go bankrupt, though the threat is not immediate.

When the proposal was unveiled in January, the government said the reforms were necessary to prevent a projected 13.5 billion euro ($14.7 billion) hole opening up in the pension system in 2030.

During an interview with two of France’s main television networks Wednesday, Macron said the bill should be enacted by the end of this year. He also defended the decision to push through the reform as financially necessary, no matter how unpopular it was.

“It’s in the greater interest of the country. Between opinion polls and the national interest, I chose the national interest,” Macron said.

— CNN’s Joseph Ataman and Olesya Dmitracova contributed to this report.