MINNEAPOLIS (AP) — Gov. Tim Walz outlined a “battle plan” Thursday to keep Minnesota long-term care residents and workers safe against COVID-19, which so far has claimed the lives of more than 400 residents of nursing homes or assisted-living facilities in the state.

Walz told reporters that the state is “prepared to go very much on the offensive” to reduce illnesses and deaths at nursing homes, where residents are more susceptible to the coronavirus because of age, underlying medical conditions and close quarters.

Walz, whose mother was a licensed practical nurse at a nursing home, said Minnesota is prepared to go “full force” on “a battle plan about dealing with these long-term care facilities — reducing the death, reducing the infections and tackling this.”

His plan includes expanded testing for the coronavirus for residents and workers at long-term care facilities, creating “strike teams” to quickly conduct on-site testing, getting personal protective equipment for facilities facing outbreaks, activating the Minnesota National Guard to maintain staffing levels and requiring facilities to exclude sick workers and those testing positive.

State health officials on Thursday said another 17 residents of nursing homes and assisted living facilities have died. Minnesota’s COVID-190 death toll rose 23 on Thursday to 508. Of the total number of deaths, 407 people lived in long-term care or assisted-living facilities.

In addition, 786 people have tested positive since Wednesday, bring the number of coronavirus cases in Minnesota to 9,365.

The number of cases in Lyon County increased from 11 to 15 Thursday.

State Health Commissioner Jan Malcolm said less than 1% of Minnesota’s population lives in long-term care facilities but that 15% of the state’s COVID-19 cases and 80% of deaths are among residents of long-term care.

A suburban Minneapolis nursing home that has been a repeat violator of care standards became the site of one of the state’s largest coronavirus outbreaks with 44 deaths and another 68 residents sickened by COVID-19.

North Ridge Health and Rehab in New Hope said it has a large number of infections because of the size of the facility, which is home to about 300 residents, making it the largest long-term care facility in the state.

North Ridge has struggled to meet care standards in the past. The facility has been fined $117,000 by federal regulators and cited for dozens of health and safety violations over the last three years, the Star Tribune reported.