OAKLAND -- Forty members of a violent East Oakland gang have been indicted by a federal grand jury on drug trafficking, identity theft and firearms possession charges, according to the United States Attorney's office.

They face fines ranging from $250,000 to $8 million and prison sentences ranging from five to 40 years. To date, 65 members or associates of the 100-member gang have been arrested and charged with various state and federal offenses as a result of a joint Oakland police, Drug Enforcement Agency and Secret Service case that started 18 months ago, initially as a narcotics and related violence investigation.

Thirty one of the defendants are alleged to have sold heroin and cocaine daily at 82nd Avenue and Birch Street and 72nd Avenue and Spencer Street, which are controlled by the gang, authorities said.

"Illegal open-air drug markets operating on our street corners in East Oakland beget violence and other criminal activity," said United States Attorney Melinda Haag in a statement.

The indictments come about two weeks after Wynn Brewer, 30, of San Leandro; Patrick O. Shields, 29, of San Leandro, who is in federal prison for a gun conviction; Cyrico Robinson, 25, of Oakland; and Willie Pope, 32, of Oakland,, leaders in the gang, were charged in Alameda County Superior Court in a suspected murder conspiracy plot

Authorities said they were part of a group that hatched a plan to kill a gang rival that failed after Oakland police fatally shot two other suspected members May 18, 2011, in the Upper Fruitvale district as they were on their way to do the killing.