Grocery workers at Kroger's stores in Kentucky, Ohio and West Virginia have gone on strike, forcing the US supermarket retailer to close its stores there.

More than 2,000 members of the United Food & Commercial Workers union approved the strike after rejecting the company's contract offer, reported Dow Jones International News.

A spokesman for the company said it planned to close all 44 stores in the three states at midnight on Monday, leaving only the company's pharmacies open.

Meanwhile, in Southern California, grocery workers at Kroger's Ralphs and Pavilions stores, Safeway's Vons and Albertsons' outlets continued with their strike.

In Missouri, around 10,000 United Food & Commercial Workers members have been on strike since last Tuesday at the St Louis area's three largest local supermarket chains, one of which is owned by US food distributor Supervalu. The 96 affected stores have hired temporary replacement workers and cut back hours, reported Dow Jones.