Checkout issues hit Amazon on Prime Day

Amazon says it's "working to resolve" issues with customers unable to check out and purchase items during one of the retailing giant's biggest shopping days.

The company issued a brief statement on Twitter following reports on the social media services customers could not add items to their cart. Some said the tech problems resulted in missed Prime Day deals.

Some customers are reporting difficulty with checkout. We're working to resolve this issue quickly.

— Amazon (@amazon) July 12, 2016

Every time I tried to add something to my cart from #primeday this morning on @amazon I received a "Add to Cart Failed - Retrying."

— Ashley (@AshDee04) July 12, 2016

#AmazonPrimeDay When I try to add to cart I'm getting this " Add to Cart failed. Retrying " Come on @amazon !! pic.twitter.com/u5ZjcBxaz3

— Michael B (@mabcmb) July 12, 2016

Amazon launched Prime Day last year as a "shopping holiday" similar to Black Friday,Cyber Monday, or Singles Day, which generates massive revenue for Chinese retailing giant Alibaba.

Last year, Amazon received orders for 34.4 million items worldwide despite complaints on social media questioning the value of the offered deals.