By Alex Dobuzinskis
(Reuters) - Inmates at a Delaware prison were still holding two correctional staff members hostage on Wednesday night after releasing two others during an uprising at the facility, state officials said.
One of the released hostages, an officer, was taken to a hospital with non-life threatening injuries, Delaware State Police spokesman Sergeant Richard Bartz told reporters.
All those held at the James T. Vaughn Correctional Center in Smyrna were state Department of Correction employees.
Officials previously said a total of five staff members were taken hostage, but later lowered the number.
Armored vehicles, SWAT teams and emergency medical personnel converged on the prison, the News Journal of Delaware reported, and aerial video from WPVI television showed dozens of uniformed officers amassed in formation.
"We've put all the resources that we have to bear to get our employees out," Delaware Governor John Carney told a news conference on Wednesday evening.
Inmates were demanding improved conditions and wanted to speak with senior officials, the website of the News Journal of Delaware reported, citing phone calls with people inside the prison that were relayed through relatives of prisoners.
The first officer was released by inmates at the prison, about 40 miles (64 km) south of Wilmington, on Wednesday afternoon and inmates released the second officer in the evening, state officials said. The second officer's condition was not immediately known.
More than 20 inmates caught up in the uprising were released during the day, Department of Correction Commissioner Perry Phelps told reporters.
A correction officer radioed for help on Wednesday morning from the C building, which houses more than 100 inmates, Bartz said.
The News Journal reported receiving a call from a woman who said her fiancé was an inmate being asked to relay demands, and that the voice an of unidentified man was patched onto the line.
"Working with the Department of Correction, the FBI and the Delaware State Police will continue negotiations to obtain a peaceful and safe resolution," Bartz said on Wednesday afternoon.
Robert Coupe, secretary of the Delaware Department of Safety and Homeland Security, said later: "Once this matter is resolved safely, then that will be the time to talk."
The men's prison holds about 2,500 inmates, including some sentenced to the death penalty, according to the prison's website.
(Reporting by Alex Dobuzinskis in Los Angeles; Additional reporting by Laila Kearney, Daniel Trotta and Ian Simpson; Editing by Chris Reese and Peter Cooney)