The Chinese mainland and Taiwan started direct air and sea transport and postal services on Monday morning, the latest step to improve once-strained ties.

Formerly, air and sea movements -- including mail -- had to go by way of a third place.

The direct daily transport started as a mainland-based Shenzhen Airlines flight took off from the Shenzhen Airport for Taiwan at 7:20 a.m.. More than 40 minutes later, a Taiwan-based TransAsia Airways jetliner left Taipei for Shanghai.

The flight time from Shanghai to Taipei has been cut by more than one hour, to 80 minutes, as planes are no longer required to fly through Hong Kong's airspace, a detour that the Taiwan authorities formerly insisted on citing security concerns.

The Mainland's State Council Taiwan Affairs Office Executive Deputy Director, Zhang Lizhong, said the start of direct flights marked a key step in the peaceful development of cross-Straits relations.

The Shenzhen Airlines plane carrying the first group of mainland tourists from Shenzhen goes through a welcome water fountain at the Songshan airport in Taipei December 15, 2008. Passenger and cargo vessels owned by mainland and Taiwan companies will sail directly across the Straits subject to official approval.[Agencies]

"Given the global financial crisis, cross-Straits direct flights started at exactly the right time," Zheng said at a ceremony in Shanghai. Direct links "will help the mainland and Taiwan jointly overcome the current (economic) difficulty," Zheng said.

Under a historic agreement signed by the mainland and Taiwan in early November, the two sides agreed to launch charter cargo flights between two mainland terminals, Pudong in Shanghai and Guangzhou airports, and two Taiwan terminals, Taoyuan and Kaohsiung.

There will be 60 return cargo flights per month, evenly divided between mainland and Taiwan airlines.

The two sides also agreed to launch regular passenger charter flights, which formerly only flew on weekends and the four major traditional festivals.

The mainland agreed to open another 16 terminals for passenger charter flights, besides the five already opened, while Taiwan has already opened eight terminals. The number of flights will increase to 108 every week, also divided evenly, with the number to be adjusted according to demand.