Several thousand firefighters marched through central Paris Thursday to demand a bonus for the upcoming Olympic Games in the French capital and threatening to strike, an AFP journalist saw.
Protesters set off smoke bombs and threw large firecrackers on the Place de la Republique, prompting the police to remove several demonstrators.
Nine unions had called for a day of action on Thursday, warning of possible strikes.
The firefighters and personnel from the departmental fire and rescue services (SDIS) demanded more staff, appropriate medical care and a bonus for their involvement in the Games in line with payments offered to police.
"We demand equal treatment with regards to the Olympic Games bonus. We want to be treated like the police", CGT union representative Sebastien Delavoux told AFP, saying the police "have obtained bonuses ranging from 1,500 to 1,900 euros."
Paris's police prefecture did not immediately respond to a request for comment on the rally.
The French capital, which has not hosted the Games in 100 years, is on a heightened security alert for the Olympics.
The Olympics will run from July 26 to August 11, followed by the Paralympics from August 28 to September 8.