The leader of the Chinese city of Nanjing is under investigation for "severe violations of discipline and law", Beijing's corruption watchdog said, the latest in a series of probes against senior party officials.

"Nanjing city party secretary Yang Weize, suspected of severe violations of discipline and law, is now under investigation," the party's Central Commission for Discipline Inspection said in a statement late Sunday.

It gave no further details but the phrase is usually code for graft, which has become endemic in China.

Just over a year ago, Nanjing's mayor Ji Jianye was removed for corruption, and prosecutors said in December that he would be tried for bribery.

Ji was expelled from the ruling party last January for having "received a huge amount of money and gifts either by himself or through his family members".

It was unclear whether the two cases were linked, the China Daily newspaper said Monday.

Yang, 52, who held the post since early 2011, has spent his entire political career in his native province of Jiangsu, of which Nanjing is the capital.

His previous posts include party secretary of Wuxi city and mayor of Suzhou, as well as jobs in the province's transport department, according to his official biography, which remains online.

Chinese leader Xi Jinping launched a drive against corruption after he came to power in late 2012, vowing to target both high-level "tigers" and low-ranking "flies".

But analysts say China has failed to implement institutional safeguards against corruption, such as an independent judiciary and free media, leaving anti-graft campaigns subject to the influence of politics.

In another recent case believed to involve corruption, a Chinese assistant foreign minister, Zhang Kunsheng, has been dismissed from his post and placed under investigation, the foreign ministry said on Friday.