CHENGDU, June 26 (Xinhua) -- Seventeen trains have been delayed or cancelled in southwest China's Sichuan Province as of Tuesday noon, due to heavy rain, local authorities said.

The railway authorities closed a section of the Baoji-Chengdu Railway, a key line linking Baoji City in Shaanxi Province with Chengdu in Sichuan, as rising river levels threatened passenger safety, according to China Railway Chengdu Group.

Several railway stations in Sichuan are offering ticket changes and refunds.

China's national weather observatory issued a yellow alert for rainstorms Monday, as heavy rain will sweep most parts of the country.

China has a four-tier color-coded weather warning system, with red the most severe, followed by orange, yellow and blue.