It takes about eight hours to fly from Shenzhen, an affluent city bordering Hong Kong, to Kashgar in Northwest China's Xinjiang Uyghur autonomous region.

It was the longest domestic flight route when Hainan Airlines started operating it last October to connect China's oldest special economic zone with its youngest, with a stopover at Urumqi, the capital city of Xinjiang.

Despite the distance of more than 5,000 km between the cities, Shenzhen was designated by the central government in 2010 to offer one-on-one assistance to the urban area of Kashgar, and one of its 11 counties - Tushkurgan - which borders Pakistan, Afghanistan and Tajikistan.

The southern city government plans to invest about 700 million yuan ($113.6 million) this year to support the economic and social development of Kashgar and Tushkurgan, according to the representative office of the Shenzhen government in Kashgar, which is the frontline headquarters.

The financial input usually accounts for 0.6 percent of Shenzhen's city-level fiscal income each year. This year, the Shenzhen government provided an extra 200 million yuan to build a comprehensive university in Kashgar, said Luo Jianpeng, command general of the frontline headquarters.

The southern city has invested roughly 2.8 billion yuan in 127 projects since 2010, he added.

"It's critical to develop the economy of Kashgar so that people can have jobs and make money, which is good for the peace of southern Xinjiang," said Luo, who also holds the position of deputy Party chief of Kashgar and its surrounding villages.

Kashgar, the biggest city in southern Xinjiang, has had a number of terrorist attacks the past few years.

"When people are poor, with no jobs, they are more inclined to be persuaded by terrorists and take extreme actions," Luo said.

At least half of the annual investment from Shenzhen goes to the development of an industrial park and a new city - two projects that can create jobs and a better living standard, Luo said.

The Shenzhen Industrial Park, covering 3.3 sq km, has attracted about 10 billion yuan in contractual capital from 23 companies, of which 950 million yuan has been invested, government figures show.

Some of the companies are involved in the green sectors of new energy, new materials, environmental protection and solar energy development.

"These companies could create at least 2,000 jobs. We expect such vacancies will increase further with a growing number of companies moving in," Luo said.