China's top environment watchdog delivered verbal warnings to companies and a local government on Thursday to promote greener growth.

The Ministry of Environmental Protection gave verbal warnings to senior officials with Luliang City in north China's Shanxi Province and the Aluminum Corporation of China Ltd. as they failed to deal with pollution cases appropriately.

Pulp leaked from a subsidiary of Aluminum Corporation of China Ltd. and flowed into a tributary of the Yellow River on Nov. 2. Neither the local government nor the company were effective in reporting or dealing with the pollution.

This is the second time Luliang has been warned over pollution in the past 18 months and the environment protection ministry also pointed out that several other branches of Aluminum Corporation of China Ltd. pose pollution risks.

The two parties must deliver rectification plans within 20 working days.

The verbal warning mechanism has been in place for more than a decade but only started to target local governments in 2014.