PARIS (AP) — France’s interior minister announced plans on Monday to open two centers to shelter migrants who return to the northern port city of Calais, determined to get to Britain despite the closing of a vast makeshift camp in Calais last fall.

Interior Minister Gérard Collomb, who estimated the number of migrants who have returned to Calais at about 400, said that so far this year, more than 30,000 attempts had been made to sneak into the ferry port or the Eurotunnel train station, or to jump onto trucks heading to Britain.

Mr. Collomb also ordered a report on accusations of police mistreatment of migrants in France. Last week, Human Rights Watch said the police had been “routinely” using pepper spray on refugees, including when they were sleeping.

Calais was the site of a sprawling, slum-like camp for as many as up to 7,000 refugees and asylum-seekers before the French government closed the camp in October. Most of the camp’s inhabitants were taken by bus to centers around France.