Britain's supermarket chains sought this week to safeguard supplies for their most frail customers, as the sector buckles under pressure from much-criticised stockpiling as a result of coronavirus panic. Sainsbury's said in a statement on Wednesday that it would open its doors to only elderly and vulnerable people for the first hour of trade on Thursday. Rival British food chain Iceland, which specialises in frozen food, had already announced on Monday that some of its stores would open one hour earlier to enable older customers to purchase essentials. Smaller supermarket chain Booths, based in northern England, has recommended that only vulnerable and elderly shoppers use its stores for the first few hours of each day. And all the nation's major supermarket chains have curbed the number of in-demand items -- like toilet roll and antibacterial wipes -- that people can buy. rfj/bcp/pma