SHANGHAI / XI'AN - In the week following Spring Festival, online retailers and delivery services were overwhelmed by a flood of orders from customers unable to access certain virtual stores due to holiday closures.

Four employees in Shang Feike's store on Taobao, China's largest online shopping platform, had to work four hours of overtime a day to pack goods and send them by courier.

"We have had about 100 orders every day after the holiday, which is almost double our normal amount," said Shang, whose store sells skin care products and cosmetics.

The store closed on Jan 19 and restarted business on Jan 29, the first working day after the holiday. Another 100 orders were placed during the holiday, although no customer service was provided during that period.

She said that she usually makes sure the orders placed before 5 pm are sent out on the same day. However, the employees still could not manage to pack all of the orders despite the extended work hours.

"According to my experiences in previous years, the buying peak will last for about a month," she said.

The sudden increase in the number of packages has also kept express companies busier than usual.

Huang Guanjun, manager of Yuantong express delivery company in Xi'an, capital of Shaanxi province, said that his company has witnessed a constant increase of packages in the five days following the holiday.

"We delivered about 1,700 packages yesterday, and the business will keep growing as Lantern Festival on Monday and Valentine's Day draw near," Huang said.

He said although the number of packages delivered these days was less than the average before Spring Festival, which was 4,000 per day, the business volume was still very substantial.

Chen Mingqiang, Yuantong express delivery's regional manager in Huangpu district of Shanghai, said that the increased workload is due to the fact that 80 percent of the company's business is online store orders.

"We are still handling a backlog of packages now. Hopefully they will be all delivered in a week's time," Chen said. Chen said they only had up to 30 packages a day during Spring Festival, and the number skyrocketed to 3,000 on Jan 29.

What makes matters worse is some of the couriers have not returned to work from their hometown, he said.

As two couriers in the team had not returned from holiday, the manager said he had to fill in the post by himself.

Online shoppers may find themselves anxious these days because of frequent delivery delays.

"I'm still waiting for a package I bought during the holiday. What drives me crazy is that it hasn't been sent out yet," said Chen Xiaolin, a white-collar worker in Shanghai who purchases online regularly.

Chen placed four orders during the holiday and two on the first working day. Most of the packages were sent out on Monday and Tuesday."I find that it takes one or two more days than usual for the delivery," she said.

Yuantong's Chen Mingqiang said that the company has started recruiting new couriers to meet the steadily increasing demand.