Protests over security in Spain's North African enclave of Ceuta escalated into clashes between locals and police Thursday, a month after a mass influx of migrants from Morocco. Police charged protesters at a beach after a group of demonstrators moved into the area where migrants have been sleeping, with some belongings set on fire during the disturbances, images broadcast on Spanish public television showed. Earlier on Thursday, dozens of protesters staged a sit-in to temporarily prevent Red Cross vehicles from reaching the beach to distribute food to hundreds of migrants staying in the area. Demonstrators, many waving Spanish flags, chanted “They should leave” and “Out with the Red Cross”, before they were dispersed by police. The incidents come after police late on Wednesday fired tear gas to prevent confrontations between protesters and migrants camping on the beach. More than 70,000 migrants entered Ceuta in late July, swimming or crossing on foot from neighboring Morocco in a chaotic influx that left scores dead and fueled fresh tensions within the European Union over migration. Although the vast majority returned to Morocco within hours, thousands remain in the territory, many living rough on the streets. Residents of Ceuta, which is just 18 square kilometers in size, have held regular demonstrations over what they say are security and hygiene problems linked to the influx. But tensions have risen after a military vehicle carrying four soldiers was “ambushed” in the early hours of Thursday by about 70 migrants, who attacked it with stones and other objects, a police spokesman in Ceuta told AFP. The soldiers fled and called for police assistance. Police detained 12 migrants, all Moroccan, the spokesman said. One soldier suffered minor injuries after being struck by a stone. The motive for the attack was not immediately clear. “The tension in the city of Ceuta is very high” because there is “no response” from the government and “we feel abandoned,” Kissy Chandiramani, the autonomous city's finance councilor, told news radio SER Thursday. But she appealed for calm, saying people had the right to protest but warning that growing hostility would not resolve the crisis. Also, Justice Minister Felix Bolanos appealed for calm, telling lawmakers in Madrid that authorities were working “without rest” to restore normality to the territory. Prime Minister Pedro Sanchez has faced mounting criticism from Ceuta's authorities and residents, who say Madrid reacted too slowly to the mass arrival. The government has in recent days moved to expand shelter for migrants and speed up efforts to determine who can be returned to Morocco. The head of Ceuta's local government, Juan Vivas, said peaceful protests “to demand the return to normality” were justified, but warned that authorities would take action against anyone who commits acts of vandalism. “We totally reject the use of any kind of violence,” he said in an institutional address. “No one can or should take the law into their own hands. The defense of Ceuta and the interests of its people can only be pursued through legality,” Vivas added.