The issues are a result of a “dramatic increase in the rate that people are shopping online,” Amazon said in a blog post that was updated on Saturday. Some popular brands and items in the “household staples” categories were out of stock, while Amazon said some of its “delivery promises are longer than usual.”

“In the short term this is having an impact on how we serve our customers,” Amazon said in the blog post. “We are working around the clock with our selling partners to ensure availability on all of our products, and bring on additional capacity to deliver all of your orders.”

Amazon added a notice to the top of its marketplace this weekend that reads: “Inventory and delivery may be temporarily unavailable due to increased demand. Confirm availability at checkout.”