ANNAPOLIS, Md. (AP) — Maryland authorities say 18 people, including two correctional officers, have been indicted in a prison corruption case.

State prosecutor Emmet Davitt announced Thursday that six inmates and 10 outside facilitators also have been indicted.

Maryland Gov. Larry Hogan speaks at a news conference at Jessup Correctional Institution in Jessup, Md., Thursday, Jan. 11, 2018, to announce indictments against two of the prison’s corrections officers for allegedly attempting to smuggle in contraband for inmates that included drugs and cell phones. Standing behind Hogan are Stephen Moyer, secretary of the Maryland Department of Public Safety and Correctional Services, second from left, Maryland State Police superintendent William Pallozzi and a Jessup corrections officer. (AP Photo/Patrick Semansky)

The charges include conspiracy to distribute controlled dangerous substances, conspiracy to commit bribery, bribery and the smuggling of contraband such as narcotics and cell phones.

The year-long investigation into corruption at the Jessup Correctional Facility was the result of a joint probe by the state prosecutor’s office, a special investigative unit in the state corrections department and the Maryland State Police.

A television news photographer films confiscated cell phones as officials prepare to return them to a box of evidence following a news conference at Jessup Correctional Institution in Jessup, Md., Thursday, Jan. 11, 2018. Maryland Gov. Larry Hogan and State Prosecutor Emmet Davitt announced indictments against two of the prison’s corrections officers for allegedly attempting to smuggle in contraband for inmates that included drugs and cell phones. (AP Photo/Patrick Semansky)

Authorities have been investigating prison corruption for years in Maryland. In November, 26 people were indicted in a separate case, including a correctional officer who served as a high-ranking gang member.