PARIS — Many French trains stood still, schoolchildren played instead of studied and post offices were shuttered as workers nationwide went on strike today to protest President Nicolas Sarkozy's plans to raise the retirement age to 62.

Nearly 200 marches and protests are planned for several cities over a broad reform to the money-losing pension system, part of efforts around Europe to cut back on growing public debts.

In the capital, while some commuters were unaffected by the strikes, others had to cram into overcrowded buses and subway trains because of strikes by drivers.

Hundreds of passengers were stranded at Rome's main train station Wednesday when the overnight train to Paris was canceled because of the strike. Authorities were putting the passengers on buses instead. Swiss national railway company SBB said about 60 percent of trains between France and Switzerland have been canceled because of the strike.

The French civil aviation authority, DGAC, asked airlines to cancel 15 percent of their flights out of Paris' Charles de Gaulle and Orly airports because of strikes by air traffic controllers. Air France said all of its long-haul flights would remain unaffected.

France has one of Europe's lowest retirement ages, allowing workers to retire at 60 in most sectors. The government says the reform to the money-losing pension system is an "obligation," given France's burgeoning deficit and its aging population.

Unions say money for the pension system should come from higher taxes or charges on those who are still working, and see cost-cutting in the pension system as an attack on a hard-fought way of life.

The French measure pales in comparison with more drastic changes elsewhere in Europe. Germany, for example, plans to gradually raise its retirement age from 65 to 67, starting in 2012.