(Photo: Xinhua)

LOS ANGELES, May 9 (Xinhua) -- A total of 792 inmates at a federal prison in Central California have tested positive for COVID-19, making it the worst-hit in US federal prison system, US news outlets reported on Saturday.

Nearly 70 percent of the inmates at Federal Correctional Institution Lompoc have tested positive, exploding by more than 300 in recent days, reported the Los Angeles Times, citing prison officials.

Eleven staff members are also infected at the Lompoc facility, which houses 1,162 low-security inmates. A military mobile hospital has been built on the grounds to cope with the growing number of stricken patients, according to the Los Angeles Times.

The increasing totals come days after the Federal Bureau of Prisons announced earlier this week that it would substantially expand testing starting at detention and quarantine sites throughout the federal prison system.

Nearly half of the inmates at another federal prison in California, the Terminal Island Correctional Institution in San Pedro, had tested positive for COVID-19, the Federal Bureau of Prisons confirmed last week.

A total of 644 inmates at the Terminal Island Correctional Institution have contracted COVID-19. Federal Correctional Institution Lompoc along with Terminal Island Correctional Institution now account for nearly half of all the federal inmates who have tested positive nationwide, the Los Angeles Times reported.

The Federal Bureau of Prisons reported that a total of 3,330 inmates nationwide have tested positive for COVID-19 as of Saturday throughout the system that holds about 151,000 inmates. There have been 46 federal inmate deaths attributed to COVID-19 disease, according to the bureau.