Warehouse “blips” have affected deliveries by online grocer Ocado today, but the retailer insisted only a comparatively small number of shoppers have been affected.

Ocado shoppers vented their frustration about non-arrival of deliveries on social media site Twitter and the retailer’s own feed was dominated for several hours by responses to customer enquiries about delivery problems.

A spokeswoman said that because of the online nature of Ocado’s business it was natural that customers should use social media to comment upon their experience and contact the retailer, but the number involved was not “significant”.