Soldiers of the People's Liberation Army (PLA) Marine Corps clean their rifles inside a tent during a military drill at a military base in Taonan Thomson Reuters BEIJING (Reuters) - China's military can only achieve its modernization goals if it respects the law, the Central Military Commission said on Thursday, offering a warning to the armed forces which have reeled from a series of graft scandals.

The government has announced investigations into more than a dozen senior military officials on serious corruption charges.

Many of those implicated have ties to a scandal involving former top military officer Xu Caihou, who retired as vice chairman of the powerful Central Military Commission in 2013.

Authorities announced last year they were investigating Xu for graft.

Serving and retired military officers have said graft in the armed forces is so pervasive it could undermine China's ability to wage war.

In the latest call to the military to uphold the law, the Central Military Commission, which is headed by President Xi Jinping, said the armed forces were a crucial part of overall efforts to boost the rule of law.

"A modern country by necessity is one that is one with rule of law, and a modern military is by necessity one that has rule of law," the commission said in an order approved by Xi and reported by the official Xinhua news agency.

"The more modern the military is, the more informatized it is, the more it needs to follow the rule of law," it added.

Xi has vowed to eradicate corruption in the 2.3 million-strong armed forces which are in the midst of an ambitious modernization program, including the development of anti-satellite missiles and stealth jets.

The program has jangled nerves around the region as Xi takes a more combative approach to disputes such as rival claims over the South China Sea.

The Central Military Commission's latest order, written in typically turgid Communist Party phraseology, made no specific mention of corruption cases nor offered new guidance on how to fight graft.

Instead, it urged the armed forces to "dare to assume the historic revolutionary mission of the new generation and proactively throw yourselves into the great practice of a military which follows the law".

(Reporting by Ben Blanchard; Editing by Robert Birsel)