Paris's Louvre museum closed on Wednesday following a walkout by staff members who are protesting what is said to be a rising problem of pickpockets haunting the famed Paris museum's vast galleries

Staff at the museum said thieves, some of them children, were targeting both employees and tourists. Two hundred workers took part in a strike organized by the SUD union, according to AFP news agency.

The secretary general of the national union for museums (SNMD), David Maillard, said petty thieves were multiplying at the site, visited by nearly 9 million people each year.

"There are thefts and threats every day. The guards are fed up with being assaulted by pickpockets," Maillard said according to Reuters.

About 100 employees gathered in front of Paris' Ministry of Culture at lunchtime where a delegation from the museum was received. The Louvre claims to be the most visited art museum in the world with almost 10 million visitors in 2012.

Paris police regularly patrol the city's most crowded tourist sites, such as the Eiffel Tower and the Louvre.

But thieves who often operate in organized gangs are a constant frustration for authorities as they are easily able to exploit tourists and can lose themselves in crowds.

"There have always been pickpockets at the Louvre and in tourist locations in Paris, but for the last year-and-a-half the gangs have become increasingly violent," said museum supervisor Sophie Aguirre.

"Their modus operandi has become more complex. Nothing can stop them."

Officials have been unable to say when the museum will reopen.