A family was attacked after quarreling with a tour guide on a trip to Badaling Great Wall over the recent Chinese New Year holiday, a time when 7.65 million visitors flocked through the city's gates.

Cui Jianguo and his family, from Zhangjiakou in Hebei province, were handed a flyer last Sunday outside the National Stadium for a one-day-tour to the wall, Beijing Times reported yesterday.

The Hebei family was picked up by a minibus near Guanzhuang at 4 am on Monday morning and taken to Xicheng district, then transferred onto a coach.

A female tour guide on the bus told Cui and his wife to seat their 9-year-old twin sons on their laps.

"She spoke us in a very impolite way, so we complained. We never thought she would get so mad at us," Hu Lin, Cui's brother-in-law, was quoted as saying.

Hu said the tour guide asked them to get off the vehicle but they refused.

"The woman rounded up seven or eight guys from the area who beat us up," Hu said.

According to medical records from Beijing No.2 hospital, Cui received a skull fracture and a wound behind his left ear, the newspaper reported.

Hu's hands were also injured, and the clothing of both men was damaged Local police said they have detained two people, who claimed they were licensed tour guides trying to stop the fight.

The rented coach belongs to the Beijing Automotive Group. The company dodged questions about who had rented their vehicle. Xicheng police is investigating the case.

"It is quite possible that the trip was arranged by an unlicensed travel agency," Song Jun, a press officer from the Beijing tourism administration, told METRO yesterday.

He said unlicensed travel agencies are a big problem for the Beijing tourism market. The administration is trying to regulate the market, but said it cannot do it alone.

"We are cooperating with Beijing police, urban administration and many other government agencies. We strongly suggest all travelers go to licensed agencies and not fall for random adverts," he said.

The recent Chinese New Year holiday saw a rise of more than 5 percent in visitors to Beijing, compared with last year. The tourism income hit almost 3 billion yuan and an 11.8 percent growth.

According to Ctrip.com, the biggest online travel agency in China, Beijing has taken over Shanghai as the most popular city.