Some online shoppers who placed their holiday orders at BestBuy.com will not receive their items as expected by Christmas, the consumer electronics chain said today. An unexplained problem will delay shipments of orders made over Thanksgiving weekend and the following week, Best Buy Co. says.

Best Buy is No. 11 in the Internet Retailer Top 500 Guide.

“Due to overwhelming demand of hot product offerings on BestBuy.com during Thanksgiving weekend and the following week, we have encountered a situation that affected redemption of less than 1% of our customers’ online orders during that timeframe,” the chain says in a statement. “We are very sorry for the inconvenience this has caused and we have notified the affected customers.”

Best Buy did not describe the products, and a spokeswoman for the chain said she did not know the problem’s cause.

On Best Buy’s Facebook page this week, at least one consumer complained of ongoing problems with getting products shipped in time for Christmas. A consumer who identified himself as Daniel Keehn said he ordered unspecified products at the chain’s e-commerce site Monday and said that when placing the order delivery was confirmed for Dec. 23 or Christmas Eve. “Today when I check my tracking number it says its [sic] arriving on 12/27,” the consumer wrote.

Lynn Lanphier, the chain’s director of digital analytics, will speak at the 2012 Internet Retailer Conference & Exhibition in a session entitled “The new age of analytics: Creating a data strategy that leads to increased sales” on June 7 from 3:45 p.m. to 4:15 p.m.