At least nine pigs' heads were found outside several mosques in the Paris region on Tuesday, the city's police chief said -- an incident that has sparked alarm over rising anti-Muslim hatred. Pigs' heads have been left in front of certain mosques... Four in Paris and five in the inner suburbs, Laurent Nunez told a press conference, adding that officers were not ruling out the possibility of finding more. Police have opened a probe into incitement to hatred aggravated by racial or religious discrimination, Nunez said, calling the acts despicable. The consumption of pork is considered haram -- forbidden in Islam -- as the meat is believed to be impure. Several of the heads had the surname of President Emmanuel Macron scrawled on them in blue ink, the Paris prosecutor's office told AFP. Nunez said there could be parallels with past incidents linked to foreign interference but urged extreme caution. In early June, three Serbs were charged over the vandalism of Jewish sites in a case investigators suspect was backed by Russia. France is home to the largest Muslim community in the European Union, as well as the largest Jewish population outside Israel and the United States. Several EU nations have reported a spike in anti-Muslim hatred and antisemitism since the Gaza war started in October 2023, according to the European Union Agency for Fundamental Rights. Anti-Muslim incidents in France rose by 75 percent between January and May 2025 compared with a year earlier, with attacks on individuals tripling, the interior ministry said in July. Fighters from Palestinian organisation Hamas launched an attack in Israel from Gaza on October 7, 2023. Israel has responded with a relentless assault on the Hamas-run Gaza Strip. -'Anti-Muslim hatred'- The incidents around Paris drew swift condemnation from political and community leaders. Macron met with representatives of the Muslim community in the capital following the incident to express his support, his office told AFP. Paris Mayor Anne Hidalgo said the city had taken legal action, denouncing the racist acts. For his part, Interior Minister Bruno Retailleau called the deeds outrageous and absolutely unacceptable. I want our Muslim compatriots to be able to practise their faith in peace, he said. Chems-Eddine Hafiz, the rector of the Grand Mosque of Paris, denounced the Islamophobic acts as a new and sad stage in the rise of anti-Muslim hatred. Bassirou Camara, head of anti-discrimination group Addam, told AFP he feared an escalation. We have been raising the alarm for months and we are not being heard, Camara said. What will be the next step? Throwing pigs' heads at worshippers or physically assaulting them?