FORTALEZA, May 3 (Xinhua) -- Police fired teargas and stun grenades on Sunday to quell rioting fans after Brazil's Ceara state final at the Castelao Arena, one of the venues used at last year's World Cup.

Fortaleza fans invaded the pitch after their team secured the title with a 4-3 aggregate victory over two legs against Ceara.

Local media reported that Ceara fans soon followed, leading to a wild brawl involving hundreds of people.

According to the Estado de S.Paulo newspaper, television camera crews were attacked and robbed while several journalists fell unconscious due to the effects of tear gas.

Fans also ripped up seats and vandalized player dugouts.

The 63,000 Castelao stadium hosted six matches during last year's World Cup after a 225 million-US dollar revamp.

Violence also marred Sunday's Rio Grande do Sul state final between Gremio and Internacional in the southern city of Porto Alegre.

After seeing their team lose 2-1 on aggregate, Gremio fans damaged seats at the Beira-Rio stadium - also a 2014 World Cup venue - and clashed violently with rival supporters.