Kroger (KR -0.67%) revealed fresh details on Wednesday about its sales trends as COVID-19 fears drove shoppers to its supermarket chains for stock-up purchases in recent weeks.

In an operating update, the country's biggest grocery store chain said demand began spiking in late February before soaring through most of March. Comparable-store sales jumped 30% for the month, management estimated, compared to around 2% gains in recent quarters. "The demand has been broad based across grocery and fresh departments," executives said. Kroger's digital channel is seeing a similar lift in customer interest.

A shopper walks the grocery aisles.

Image source: Getty Images.

Kroger noted a tapering of customer traffic late in the month as shoppers adjusted to a sharply reduced pace of dining, work, social, and travel outings. Still, the retailer is prepared for significantly higher volumes in the weeks to come and has scaled up hiring while providing bonuses to frontline employees through April 18.

Management said it is too early to predict where food consumption levels will settle after social distancing measures are lifted. Yet the company feels confident in affirming its prior 2020 outlook that called for comps to rise by at least 2.25%, which would mark a third straight year of accelerating sales growth.