MONTEVIDEO: Some 30 fans were arrested and 18 police injured in fights at a Copa Libertadores match, Uruguay's Interior Ministry said on Thursday.

The violence seemed to be touched off just after Brazilian club Palmeiras club defeated Uruguay's Penarol 3-2 in Uruguay.

Videos show chaos on the field at the final whistle on Wednesday. Players chased and taunted each other in the absence of much security. Fans in the stands also got into the act.

"It started on the field, and it seemed incongruous that the players asked the fans not to fight when the fights had already started on the field," Interior Minister Eduardo Bonomi said on Thursday.

The ministry said a firearm was taken from at least one policeman, and six police vehicles were damaged.

CONMEBOL did not offer an immediate comment.

CONMEBOL's top officials, at a meeting on Wednesday in Chile, viewed an auditor's report that showed its three presidents from 2000-2015 illegally transferred $128.6 million to personal accounts, suspicious accounts, or unauthorised third-party accounts.