BEIJING, June 13 (Xinhua) -- China's top economic planner Tuesday issued a risk warning as some Chinese companies have issued offshore corporate debt without filing registrations to the government.

The companies on the National Development and Reform Commission (NDRC) warning list included China Water Affairs Group and Mengniu Dairy, one of the country's dairy giants.

The NDRC said companies who seek to issue offshore corporate bonds should strictly follow government rules and complete registration before the issuance or file reports afterwards.

The NDRC urged companies to complete the registration process as soon as possible.

Chinese authorities have tightened financial regulations nationwide in recent months to ward off systemic risks in the sector and guarantee long-term growth.