With the government considering relaxing the FDI policy for railways, the home ministry and the department of economic affairs have sounded a note of caution, citing "security" concerns, especially with regard to investments from China in this sensitive sector.
In its comment on the proposal of the Department of Industrial Policy and Promotion (DIPP), the ministry said Chinese investments in such a sensitive sector should be viewed with caution, sources said.

Source - http://www.financialexpress.com