FUZHOU - Bullet trains may slow down or stop, ships have been called back to harbor and shipping lines have been suspended as tropical storm Nanmadol moves northwest toward Fujian province.

Officials at the observatory in Fujian said that Nanmadol would most likely make landfall over the southern part of Fujian, bringing gales and rainstorms.

Typhoon Nanmadol weakened to a tropical storm at around 10 am Monday after making landfall in Taiwan at 4:25 am Monday. It then moved northwest at a speed of 10 km per hour, according to the observatory in Zhejiang, Fujian's neighboring province.

To ensure absolute safety, bullet trains along the Wenzhou-Fuzhou and Fuzhou-Xiamen high speed rail lines may have to operate at slower speeds or suspend service if the surveillance system detects any hazards, according to the Nanchang Railway Bureau.

More than 1,800 local ships have returned to harbor since maritime affairs bureaus in Fuzhou, Putian, Quanzhou, Xiamen and Zhangzhou on Monday jointly activated the red warning, the highest level alert, said authorities with the Fujian provincial maritime department.

Also, the Xiamen-Jinmen shipping line, which links the mainland and Taiwan, suspended service at 2 pm Monday. Ships took shelter in Gaoqi Port in Fujian's coastal city of Xiamen, according to the Xiamen maritime affairs bureau.

The Fujian provincial maritime affairs department has already strengthened offshore patrol and inspection to ensure the safety of the ships.

Four rescue ships, three rescue jets and 65 tug boats have been put on emergency standby.

The observatory forecasts that the typhoon will coincide with an astronomical tide on Monday, and waves are expected to crest at 2-3.5 meters in Fujian's coastal areas.

It also warned local governments that the typhoon could lead to torrential flooding and landslides in some regions.

Nanmadol has brought showers to most parts of Zhejiang and ushered 70-km per hour winds into Zhejiang's coastal areas, the observatory reported.

The observatory also warned of secondary disasters that may be triggered by strong winds and torrential rain.