Authorities in Paris, attempting to discourage migrants from setting up camp, placed large boulders under a bridge near an overcrowded refugee center, the Associated Press reported Thursday.

Refugees, many of who were attempting to get to the U.K., created the campsite under a bridge by the Gare du Nord, a major train station in the northern part of the city, to try and protect themselves from the harsh winter conditions.

The makeshift camp emerged in front of La Chapelle, a refugee center that has no more beds. The center, which was set up by municipal authorities, has taken in more than 5,200 refugees since opening in November, RT reported Thursday.

An unidentified female representative from Solidarité migrants Wilson, an activist group that helps asylum-seekers in the French capital, told L’Express newspaper the limestone boulders were placed Friday, part of an ongoing police crackdown on migrants living on the street. After talking to a number of those taking refuge under the bridge, the representative said many haven’t slept in days because they lacked protection from the snow.

“They are exhausted, they [are] cold, some have not slept since Friday — we are extremely indignant,” she told L’Express.

L’Express obtained a statement from Paris Mayor Anne Hidalgo's office, saying the boulders were placed “to avoid street camping.” The city also said the boulders were relocated from a site being prepared for construction.

Dozens of Paris police officers used tear gas and batons to clear an illegal settlement known as the Jungle refugee camp in Calais on Oct. 31, highlighting a week where 2,500 migrants were removed from the streets of Paris, French Interior Minister Bernard Cazeneuve told the Telegraph. 

More than 85,000 people, many of who fled civil wars and poverty in the Middle East, applied for asylum in France in 2016, according to the Asylum Information Database, which collects information on the flood of migrants entering Europe.