A small group of maximum security prisoners, demanding a helicopter and $100,000 cash, held six hostages on the seventh floor of the city jail for three hours today before releasing them unharmed.

About a dozen prisoners, convicted felons housed in the 19-year-old city jail because there is no room for them in the Virginia state prison system, gave themselves up after a Norfolk police SWAT team carrying automatic weapons entered the jail's seventh floor.

Five sheriff's deputies and a paramedic were taken hostage at 7:55 a.m. by the prisoners, who were armed with broomsticks, electrical prods taken from the deputies, and a screwdriver. The deputies do not wear guns in the jail.

Sheriff Charles H. Leavitt, who runs the jail that occupies the top five floors of the eight-story Public Safety Building, blamed the attempted escape on "hardened criminals" the State Department of Corrections has forced him to house despite inadequate maximum security facilities.

"This is no place to hold these high-risk people," Leavitt said. Those who took part in the escape attempt included prisoners convicted of murder, rape, and armed robbery.

Six of the prisoners involved in the escape attempt were transferred this afternoon from the Nolfolk jail to a state prison in Powhatan, Va.

The Virginia prison system has been farming out its prisoners to local jails across the state for six years because of overcrowding, according to Department of Corrections spokesman Wyane J. Farrar.

There are 991 prisoners who by law should be confined in state penitentiaries but are now being held in local jails, Farrar said. Until the six inmates were transferred today, 72 of these prisoners were confined in the Norfolk city jail.

The seventh floor of the jail here, which houses 130 convicted and accused felons, was taken over this morning during sick call, according to Leavitt.

The prisoners apparently herded their hostages into a cell, began breaking windows and threw light bulbs to the street below, according to the sheriff. The inmates also dropped a handwritten note out one window, asking for a helicopter capable of carrying 15 people and $100,000 in cash.

"They had no other demands other than their bid for freedom," Leavitt said. He said most of the prisoners on the seventh floor remained in their cells and refused to participate in the escape attempt.

Norfolk Police Chief Charles D. Grant said 15 members of the city's Emergency Response Team emerged on the seventh floor from a stairway and elevator as the sheriff read a statement to the inmates over a loudspeaker system. The sheriff told them he could not agree to any of the inmates' demands.

The heavily armed policemen apparently smashed windows in a visiting area of the seventh floor to help persuade the inmates to surrender their hostages, according to the police chief.