Moroccan authorities have begun dismantling makeshift migrant camps near the Spanish enclave of Melilla, setting fire to the temporary homes of hundreds of people who were waiting to try to rush the triple fence at the border, human rights groups have said.

The raids on Mount Gourougou began in the early hours of Tuesday, said the Pro.De.In Association of Melilla. “They burned everything,” one migrant told the Spanish radio station Cadena Ser.

The man said Moroccan security forces used force to hold people back as they destroyed the camps. “They hit us on the arms, legs or on the head. I’m hurt too, they’ve cracked my skull,” he said. Some people were taken to hospital and hundreds of others were put on buses, the man said.

A 21-year-old migrant from the Ivory Coast told El Diario that he watched helplessly as authorities swept through the camp. “Several police came and they burned everything. Everything,” he said. “We couldn’t do anything. They hit us, and some people are in really bad shape.”

A video shot by Pro.De.In documents the charred remains of the camps. The human rights organisation Caminando Fronteras said more than 1,200 migrants were detained and put on buses to other parts of the country.

Migrants spend months or sometimes years living rough as they wait for a chance to jump the border fence at Melilla and enter Europe.

This week Moroccan authorities said the success of a new immigration policy meant they could now take a tougher line on illegal migrants using the country as a base from which to enter Spain and Europe. They said nearly 18,000 people who applied to a special programme to regularise illegal immigrants had been successful.

“We gave them many opportunities, and now if they don’t want to stay, Morocco will have to apply the law for the sake of security,” Charki Draiss, of the interior ministry, said on Monday. He said camps housing migrants near Melilla and Ceuta, another Spanish enclave, would be dismantled “very soon”.

His words prompted hundreds of migrants to desperately try their luck at rushing the Melilla fence. On Tuesday Spanish authorities said more than 600 migrants attempted the crossing, of whom 35 were successful. Five people were injured, officials said.

Separately, a court in Ceuta has summoned 16 Spanish civil guard agents to answer questions about their role in the drowning deaths of 15 migrants last year.

The migrants had been attempting to make their way into Ceuta by swimming around a manmade breakwater that separates Moroccan and Spanish waters. Those who made it to land accused Spanish authorities of trying to keep them at bay by firing rubber bullets at them and spraying them with teargas.

Spain’s interior minister, Jorge Fernández Díaz, said the agents did fire rubber bullets but “at the water, not at people”. He denied that the actions of the police played any role in the migrants’ deaths.