A total of 29 arrest warrants and 30 home search warrants were issued.

Twenty-seven “supporters of Benfica and Sporting” allegedly involved in clashes were arrested on Wednesday as part of a “large-scale” operation in the greater Lisbon area and on the southern bank of the Tagus, according to the PS.

The Lisbon City Command reported in a statement that the Criminal Investigation Department “is complying with 29 arrest warrants issued by the judicial authority, as well as 30 home search warrants.”

In the investigation leading up to this action, the PSP adds “cases of aggression, between groups of supporters and against the police, offenses of theft, specific damage and participation in altercations”.

Speaking to Lusa, the commissioner in charge of the operation, André Teixeira, said 26 people were arrested under arrest warrants and one in the act, in possession of a firearm.

According to the commissioner, two firearms, narcotics, firearms and bladed weapons have already been seized in the operation – which began at 07:00 and is still running at 10:00.

According to the security force, the police operation focuses on “accidental” movement in Portugal “related to the sporting phenomenon”.

Dozens of operatives associated with the criminal investigation are involved in the operation, supported by the technical police component and other public order equivalence elements of the PSP.

In the field of competence of the Republican Guard, the operation is also carried out with the support of this security force, according to the statement.