A human rights group on Wednesday slammed French police in the northern port of Calais for "routinely" using pepper spray on both underage and adult migrants.
The report from Human Rights Watch (HRW) also accused the French authorities of turning "a blind eye to the widespread reports of the abuse".
Calais was the main transit point for migrants and refugees trying to reach the U.K. until the French authorities dismantled the so-called Jungle camp in October 2016, once home to up to 7,000 people.
The local authorities have denied the claims. Pas-de-Calais prefect Fabien Sudry described the accusations as "slanderous" and in a statement said: "Police forces in Calais act in accordance with the rule of law, with the sole objective of ensuring public order and security."
Human Rights Watch said officers, particularly the riot police, used pepper spray on migrants and asylum seekers regularly "while they are sleeping or in other circumstances in which they pose no threat".
The 40-page report is based on interviews with more than 60 asylum seekers and other migrants in and around Calais and Dunkirk, including 31 unaccompanied children, over the last two months.
"It is reprehensible for police to use pepper spray on children and adults who are asleep or peacefully going about their day," Benedicte Jeannerod, HRW's France director, said in a statement.
HRW also called on the French Interior Ministry to "urgently remove obstacles to refugee protection… by either establishing an asylum office in Calais or facilitating applications in existing offices".
French Prime Minister Edouard Philippe earlier this month unveiled draft legislation aimed at improving conditions for the growing number of migrants and refugees living rough in France, and to cut asylum-application times from over a year to six months.
