NANNING - Vincent Hou, a tour guide from Brunei, speaks Mandarin thanks to practicing with Chinese tourists.

"I can speak Cantonese, Hakka, Malay, English and Mandarin, so it's no wonder that I had an accent when speaking Mandarin. But my customers from the Chinese mainland, especially the elderly, often corrected me," said Hou, whose father comes from Fujian province and mother comes from Guangdong province.

It was the first time Brunei-based Borneo Trekker Travel, Hou's employer, has attended the China-ASEAN Expo, where Brunei is this year's Country of Honor. One theme of the event is tourism, as this year marks the China-ASEAN Year of Tourism.

Hou led a growing number of Chinese tour groups in Brunei in the past year or two, thanks to more direct flights between the two countries and easier access to Brunei.

Since May 2016, Chinese tourists can apply for a visa on arrival with a 14-day stay. Direct flights have been launched between Brunei and the Chinese cities of Zhengzhou, Kunming and Nanning.

"My Chinese customers love islands, but think Thailand and Malaysia are overcrowded. Brunei is a good choice," Hou said. "It is tranquil. There are no bars or KTVs in this Muslim country."

Like Hou, many of those involved in the tourism industry in Southeast Asian countries have benefited from the China-ASEAN tourism boom.

Nearly 8,800 travel agencies in nine ASEAN countries are approved to receive Chinese tourists, according to a report published at the expo.

In 2016, more than 30 million trips were made between China and ASEAN countries, compared with 10 million in 2011. The two are each other's largest overseas tourist destinations and largest sources of tourists, said the report on bilateral cooperation in tourism.

The rapid expansion of China-ASEAN tourism has pushed ahead with the regional economic integration, said Cambodian Prime Minister Hun Sen when addressing the opening ceremony of the expo. "The development of tourism has also promoted communication of peoples' hearts."

About 830,000 Chinese tourists visited Cambodia last year, up over 20 percent year-on-year, becoming the second largest group of foreign tourists for the country.

Hun Sen said tourism remains a pillar industry for Cambodia, and it has created jobs and helped its people cast off poverty.

Favorable visa polices and improved traffic are behind the prosperity of China-ASEAN tourism, said Dai Bin, head of China Tourism Academy.

In Guangxi Zhuang autonomous region, a Chinese tourist can enjoy a one-day tour of Dongxing and neighboring Mong Cai in Vietnam by showing only his or her ID card. Self-driving trips between the two cities were allowed in 2016.

From January to June, nearly 368,000 cross-border trips were made via Dongxing, up 17.8 percent year-on-year.

Since 2000, nearly 20 documents have been signed to encourage bilateral tourism.

Among the 10 ASEAN countries, nine offer visa-free or visa-on-arrival policies for Chinese tourists. More than 2,700 flights fly between China and ASEAN countries every week.

Large railway projects are being constructed to better connect China and the bloc, including the Trans-Asian Railway.

In addition, ASEAN countries are working hard to woo Chinese tourists.

Meng Phala, vice-president of Cambodia Association of Travel Agents, said the Cambodian government has reined in "zero-package" trips featured by forced shopping. In addition, the government offers local tourist guides Chinese language courses to better serve Chinese tourists.

China is an increasingly attractive destination for ASEAN tourists. More than 3 million Vietnamese tourists visited China last year, up 46.6 percent year-on-year.

Despite the success, some obstacles remain in the tourism cooperation.

The development of traffic and tourist facilities is lagging behind in some ASEAN countries. For example, Chinese tourists to Thailand in the fourth quarter of 2016 surged by 71 percent from the same period of 2015, challenging the capacity of its airports, roads and hotels.

In addition, concerns have mounted over safety. From January 2000 to April 2014, 65 safety incidents involving tourists were recorded in the islands of ASEAN countries, such as traffic accidents and hijackings, according to the report on bilateral cooperation in tourism.

Among the worst was a bombing that killed more than 20 tourists, including seven Chinese nationals, in Bangkok in August 2015.

The increase of cybercrime, such as telecom fraud that often involves criminals based in some Southeast Asian countries, could result in tighter controls over cross-border trips, the report said.

It said more efforts are required from both sides to further reduce visa restrictions for China and ASEAN tourists, set up mechanisms to protect their rights, and develop new tourist routes.