In the week starting Nov. 11, the country's biggest online shopping day of the year, Chinese couriers delivered a total of 346 million items, jumping 73 percent from a year earlier, according to figures released by the State Post Bureau on Monday. The week's deliveries peaked on on Nov. 13, when couriers nationwide delivered nearly 6.52 million items, up 85 percent year on year. Originally designated as an alternative to Valentine's Day, Nov. 11 has been more recently turned into a virtual shopping day, or the Chinese version of "Cyber Monday," by Chinese e-commerce giant Alibaba.com. A 24-hour online shopping spree on Nov. 11 this year, fueled by heavy discounts, ended with a record high sales volume of 35 billion yuan (5.7 billion U.S. dollars), 83 percent more than a year ago. The State Post Bureau, which operates the express delivery brand EMS, said express delivery companies, faced by the onslaught of shipping, had added to their transportation fleets, purchased additional equipment and vehicles, and opened new express delivery flights. The bureau added that couriers operated round the clock every day last week except on Nov. 16 and 17. Most parcels have been delivered to buyers and there was no heavy backlog of orders. China has the world's biggest online population, with 564 million netizens as of the end of last year. About 200 million of them regularly buy goods from online shops, making them increasingly reliant on couriers. Soaring demand for delivery services has led to a boom in China's courier industry. By the end of 2012, there were some 8,000 registered courier firms, employing around 900,000 people across the country.