Hundreds of Spanish youths set fire to trash cans, knocked down telephone booths and threw bricks and bottles at riot police trying to prevent them from holding an outdoor drinking party early Wednesday in a downtown Madrid plaza.

Officials said around 60 people were injured and eight arrested in the second straight night of pitched battles between Spanish security forces and youths trying to stage what is known in Spain as a "botellon" — literally, a big bottle.

The term comes from young revelers' practice of buying spirits and large bottles of cola or other soft drinks and drinking in the street. It is common throughout Spain, but was banned a few years ago in Madrid and the region surrounding it.

The violence started Tuesday at a square in the city's Malasana district, home to many bars and restaurants, when youths in their early 20s tried to gather for a party in May 2 Square. Police stopped them and more than 20 people were hurt in the ensuing clashes.

The clashes resumed Wednesday, with an estimated 1,000 young people battling hundreds of police in riot gear, who fired rubber bullets and tear gas to disperse them.

A field hospital was set up to treat the wounded.

Police said 15 officers were injured, most lightly. But one suffered a broken arm.

A total of 44 youths were also treated.