A junior Walmart Inc. employee organized a one-day strike and other actions to protest the retailer's stance on gun sales in the wake of shootings at two of its stores in recent weeks.

Thomas Marshall, a 23-year-old category manager in Walmart's San Bruno, California-based e-commerce business, sent an email blast to the entire division that asked employees to call in sick Tuesday, leave work early on Wednesday, and sign a Change.org petition that urges the company to stop selling firearms and ammunition.

Marshall said he has received a "considerable amount of support," with about 30 employees actively involved so far. It's unclear how many decided to stay home from work Tuesday.