Paris' prosecutor has begun a probe after May Day protesters allegedly entered a famed Paris hospital and tried to force the door to its intensive care unit, reports Euronews.
But supporters of the "gilets jaunes" ("yellow vests"), who were among demonstrators during a fiery march in the French capital on Wednesday, said they were just seeking refuge from tear gas fired by police.
Thirty-two people were in police custody under charges of "gathering to commit degradations or violence," the prosecutor's office told Euronews.
They were released on Thursday evening as investigations continue, the prosecutor's office said.
Interior minister Christophe Castaner said Pitié-Salpêtrière hospital was 'attacked' by dozens of anti-capitalist militants and black blocks.
Hospital director Marie-Anne Ruder said the gate had been forced open and she saw dozens of people going inside, some wearing the protesters' trademark high-visibility yellow vests and others with their faces covered.
She called the police because of their "violent and threatening behaviour", she told France Inter radio.
"Several dozen people tried to force the door into the intensive care unit," she told RTL in a separate interview, saying the security forces had turned up 10 minutes later to remove the intruders.
Paris hospitals director general Martin Hirsch said CCTV footage showed a number of intruders trying to get in as a group of nurses struggled to hold the door shut, shouting: "Be careful, there are patients in here!"