Around 160 people, some carrying knives and stones, were arrested at a Moroccan football match on Sunday in violence which left more than 100 police officers injured, officials said.
The supporters, which included 90 teenagers, "were arrested for their alleged involvement in acts of violence, for possession of knives, drunkenness, throwing stones, causing damage and setting fire to a vehicle," said the General Directorate of National Security (DGSN) in a statement.
The violence erupted at the end of a Throne Cup game between AS FAR, the Moroccan Armed Forces club based in Rabat, and Maghreb de Fez (MAS), AFP said.
AS FAR were beaten 2-0 and their ultra fans invaded the pitch to face down rival supporters, according to local media.
Police were bombarded with projectiles as they intervened.
The DGSN reported 103 police injured while 57 supporters were also hurt.
"At this stage of the investigation, a lot of damage to the facilities at the Moulay-Abdallah stadium has been recorded. A motorcycle was set on fire and 33 police and private vehicles were also damaged," added the DGSN.
The Moroccan football federation will meet next week to discuss the violence and sanctions are expected.
Sunday's outbreak of trouble was the first since fans were allowed to return to sports grounds at the end of February after two years of closure due to the coronavirus pandemic.
However, Moroccan stadiums have been the scene of violence between supporters in recent years.
Fights frequently break out between fans of the country's two top Casablanca clubs, Wydad and Raja, including on the streets outside the stadiums.
After the death of two supporters in early 2016, the authorities disbanded groups of ultras and even banned slogans and banners on the terraces.
However, ultras were permitted to return to the grounds in March 2018.