Olympic host city Beijing and six co-hosts are making last-minute efforts to overhaul public transport systems in order to support the upcoming Olympic Games.

China's Ministry of Railway on Wednesday announced that a rapid railway linking Beijing with the co-host city Tianjin will be officially operational on August 1, one week before the Games begin.

The 120-km Beijing-Tianjin Intercity Railway would be able to run at an operational speed of 350 km per hour, MOR Vice Minister Wang Zhiguo told a press conference in Beijing.

He said the ultra-modern line would cut the traveling time between the two cities from the current 70 minutes to about 30 minutes, giving passengers including Olympic athletes and sports officials an easier commute.

"The opening of the railway before the Olympics is a good news for all of them," Wang said.

Tianjin will hold 12 Olympic football matches between August 6-15.

The newly-built state-of-art Beijing South Railway Station, with a capacity to handle over 10,000 passengers per day, will also be put in service on August 1.

Besides Beijing and Tianjin, the national railway network has detailed plans to serve Olympic events in other co-host cities such as Shenyang, Qingdao and Shanghai, said Zhang Shuguang, MOR's deputy chief engineer.

A total of 16,000 athletes, coaches and officials from around the world will attend the Beijing Olympics, which is also expected to attract some 500,000 tourists from overseas.

Ensuring the safety of public transport has become the top priority of all cities, particularly after two bus explosions in southwest China's Kunming city on July 21, which killed two passengers and injured 14 others.

Chinese police have yet to find who is behind the explosions, but denied claims by a Uygur separatist group over the weekend that it carried out a series of attacks in several Chinese cities, including Kunming.