Walmart (WMT) is the latest retailer to expand the number of coronavirus testing locations it will have operating in its parking lots.

The retail giant will open more than 20 test sites in at least 10 states by the end of April after opening two locations in the Chicago area in March, according to Business Insider. As of April 3, Walmart had completed nearly 3,000 tests at the two sites in Illinois, which were providing COVID-19 tests to first responders initially.

Walmart was one of several retailers that committed to opening COVID-19 drive-thru test sites at its stores as part of the federal government response to the virus. Other companies called upon to open test sites included CVS, Target, and Walgreens.

Walmart is reportedly working with Quest Diagnostics and the Department of Health and Human Services (HHS) to set up the locations, which will be serviced by volunteer Walmart pharmacists and HHS workers.

“We currently have three sites open, and we have plans to expand testing to multiple sites next week with the goal of having more than 20 sites in more than 10 states by the end of the month,” a Walmart spokesperson told the news outlet.

“We have been learning a lot from our initial sites so that we can get the model right and are working hard to help expand testing in areas of need as quickly as possible.”

It was unclear at the time of writing exactly where the 20 COVID-19 testing sites would be located.

Shares of Walmart stock were up 2.73% as of 11:14 a.m. EDT on Tuesday.

Walmart A Walmart sign is seen in Miami, Florida, Aug. 18, 2015. Photo: Joe Raedle/Getty Images