'But raising the five-star [People's Republic of China] flag would be out of the question here.' After talking with the ship's captain, Xu Yaofeng, harbour police said he had told them it was also international custom not to raise flags after sunset.

But the ship's crew would be 'politely advised' to raise the Taiwan flag when the sun came up this morning.

'I really don't know what kind of arrangement they made with the Kaohsiung Harbour Bureau,' said one officer.

According to international custom, ships fly the flag of the host country on their mast when pulling into port, while the flag of the country of registration is hoisted at the rear.

The Sheng Da was registered in Saint Vincent, in line with Taiwan's requirement that only foreign-registered Chinese vessels can ply cross-strait routes. But the Sheng Da flew no flags at all when it pulled into Kaohsiung.

Taipei has offered to let Taiwanese vessels raise China's communist flag when sailing into mainland ports, but Beijing has remained silent on whether mainland vessels could reciprocate in Taiwan.

Earlier, Kaohsiung harbour officials said they were glad the direct sailings finally materialised.

Sheng Da was delivering 30 containers for transshipment to Europe, the United States and the Middle East via Maersk Lines, Sea-Land Service and American President Lines.

The Sheng Da's crew will be allowed to tour Kaohsiung today. An official of Taiwan's Transport Ministry said: 'The port authorities have given the green light for the mainland crew to leave their ship.' Taiwan would normally require the mainland crew to stay on board the vessel for the duration of its stay.

The ministry official did not elaborate on the policy change but said the crew would not be allowed to make individual trips and would have to travel in a group.

A second mainland ship, Far East Glory, would reach port today, a Kaohsiung duty officer said.