BARCELONA/ROME, Sept 24 (Reuters) - A court in Sardinia released Catalan separatist leader Carles Puigdemont from custody on Friday, a day after Italian police detained him under a European arrest warrant issued by Spain, Italy"s Justice Ministry said. Spain has demanded that Italy extradite Puigdemont, who headed Catalonia"s government at the time of a vote on independence from Spain in 2017 which courts said was illegal. If extradited, he would likely to face the same Supreme Court trial that sentenced nine Catalan separatist leaders to lengthy prison terms in 2019 for their role in the 2017 attempt to break away from Spain. The hearing on Oct. 4, which the court ordered Puigdemont to attend, will decide on the legality of the European arrest warrant, the ministry said. Until then Puigdemont will not be subject to any restrictions on his movements but he will have to return to Sardinia for the hearing, his lawyer told Reuters. After leaving the prison in the city of Sassari, Puigdemont said he had thought his arrest was a possibility. "We had some news there were police officers ... We have always thought this could happen but we also knew how it could end. The decision from the European Union"s General Court is very clear ... Spain never misses an opportunity to cause a scene," he said, referring to the case related to his immunity. Spanish Prime Minister Pedro Sanchez said Puigdemont must submit to justice but dialogue was the best way to seek reconciliation with the northeastern region, a week after he relaunched talks with Catalonia"s separatist government. Catalonia"s regional leader, Pere Aragones, said the arrest complicated that dialogue. Catalonia"s regional President Pere Aragones looks on during a news conference at Palau de la Generalitat, following the arrest of former Catalan government head Carles Puigdemont in Sardinia on Thursday, in Barcelona, Spain, September 24, 2021. REUTERS/Albert Gea A person holds a sign with the picture of former Catalan government head Carles Puigdemont, who has been arrested in Sardinia on Thursday, during a protest in his support, in front of the European Parliament, in Brussels, Belgium September 24, 2021. REUTERS/Yves Herman People demonstrate in front of Italy"s consulate, following the arrest of former Catalan government head Carles Puigdemont in Sardinia on Thursday, in Barcelona, Spain, September 24, 2021. REUTERS/Albert Gea 1/6 A person holds a sign with the picture of former Catalan government head Carles Puigdemont, who has been arrested in Sardinia on Thursday, during a protest in his support, in front of the European Parliament, in Brussels, Belgium September 24, 2021. REUTERS/Yves Herman "Yesterday"s events clearly show that the Spanish state has not acted in good faith with European justice and do not help to resolve the conflict," he told reporters. Police cordoned off a major avenue in the Catalan capital Barcelona after a few hundred protesters gathered in front of the Italian consulate, waving Catalan separatist flags and chanting "Puigdemont is our president" and "Free Puigdemont." ARREST WARRANT Puigdemont, 58, has been living in self-imposed exile in Belgium since late 2017 after Spain accused him of helping to organise the independence referendum. He has served as a member of the European Parliament since 2019, but was detained by Italian border police at Alghero airport as he arrived in Sardinia from Brussels to attend a cultural event. Puigdemont was subject to a European arrest warrant issued by Spain but his chief lawyer, Gonzalo Boye, told reporters in Brussels that there were no grounds to detain him. The European Parliament stripped him of immunity in March. Italy"s Justice Ministry said in a statement it has no decision-making role in the European arrest warrant procedure and any final decision on this lies entirely with the judicial authorities. "This is in fact a different procedure from that of extraditions," it said.