As worried shoppers flock to H-E-B grocery stores — and in many instances encounter long lines and barren shelves — the retailer is urging calm amid the evolving coronavirus pandemic and is discouraging merchandise hoarding.

San Antonio-based H-E-B said March 13 on Twitter that it’s prepared for the COVID-19 coronavirus and that “we are in a strong position to keep replenishing shelves.”

“Customers shouldn’t panic, we continue to restock shelves. We encourage preparedness, not stockpiling — please buy what you need & leave some for your neighbor behind you,” H-E-B said.

In another tweet, H-E-B wrote: “We are in this as a community and it’s important to keep calm. H-E-B Partners are ready to help #SlowtheSpreadTexas.”

H-E-B’s tweets come as numerous shoppers report checkout lines snaking through H-E-B stores, and reduced or zero availability of staples like bottled water, canned soup, and toilet paper.

In Houston, Mayor Sylvester Turner pleaded with shoppers to halt panic-driven purchases.

“The world is not coming to an end,” Turner tweeted the night of March 12. “But if it is[,] all that bottle[d] water and toilet paper you are buying will not get used.”

The state’s dominant grocer, H-E-B operates more than 400 stores in Texas and Mexico. “H-E-B is business as usual and all stores are open,” the company tweeted March 12.

H-E-B posted its March 13 coronavirus tweets on the same day that:

• Govenor Greg Abbott proclaimed a health disaster in Texas.
• San Antonio confirmed its first travel-related case of the coronavirus and declared a health emergency.
• Fiesta San Antonio was postponed from April to November.
• Austin reported two presumed cases.
• Greg Fenves, president of the University of Texas at Austin, revealed his wife, Carmel, has tested positive for coronavirus and another relative was presumed to have coronavirus. All three are now self-quarantined.
• A seven-day ban on large public events took effect in Dallas.
• The Houston Livestock Show and Rodeo said it will refund all entry fees paid by exhibitors who were unable to compete. On March 11, the rodeo cancelled the remainder of this year’s event.

On March 7, H-E-B said on its website that had it had restricted the purchase of certain items “because we know limits will help protect the supply chain in Texas.”

“We understand our customers want to prepare by stocking up on the essentials. Texans must continue to prepare, but panic does not promote progress,” H-E-B wrote. “While our customers might find our supply of some products low or temporarily out of stock, please rest assured knowing that we’re maintaining close contact with our suppliers and our Partners are working around-the-clock to keep our shelves stocked.”

H-E-B also said it has temporarily discontinued in-store food demonstrations, and it’s still offering delivery and curbside pickup of orders. Furthermore, the company said it’s more frequently cleaning its stores; making hand sanitizer and disinfectant wipes available to shoppers; and stepping up employee training about hygiene and wellness.

At the corporate level, H-E-B has cut all domestic and international business-related air travel.

“As a state, we can help slow the spread of the virus by working together. H-E-B is prepared to help our fellow Texans in any situation our company and communities might face,” the company said.