China passed a wide-ranging new national security law Wednesday, expanding its legal reach over the Internet and even outer space as concerns grow about ever-tighter limits on rights.

Since President Xi Jinping came to power, the ruling Communist Party has overseen a wide-ranging crackdown on activists, while unrest related to the mainly Muslim region of Xinjiang has worsened and spread.

"China's national security situation has become increasingly severe," said Zheng Shuna, a senior official at the National People's Congress (NPC), the rubber-stamp parliament.

China was under pressure to maintain national sovereignty and at the same time handle "political security and social security, while dealing with internal society", she said.

It would "not leave any room for disputes, compromises or interference" when protecting its core interests, she added.

The standing committee of the NPC passed the law by 154 votes to nil with one abstention, officials at the Great Hall of the People in Beijing said.

It will come into force later on Wednesday when Xi signs it, the official Xinhua news agency said.

The legislation was both wide-ranging and couched in general terms, with few exact details such as sentences for violators.

The practice, which leaves the authorities ample room for interpretation, is common in China, with the government issuing detailed regulations later.

The law vows to "protect people's fundamental interests", Xinhua said, including "sovereignty, unification, territorial integrity... (and) sustainable development".

It declares both cyberspace and outer space to be part of China's national security interests, along with the ocean depths and polar regions, where Beijing has been extending its exploratory activities.

The text requires key Internet and information systems to be "secure and controllable", Xinhua said, potentially raising concerns for foreign technology companies.

The Internet -- which is subject to strict censorship in China -- was "a significant infrastructure facility of the country", Zheng said, adding that Beijing's sovereignty over it should be "respected and maintained".

Xi has made security concerns a top issue, and chaired the first meeting of the country's national security commission in April last year.

Beijing has repeatedly clashed with Washington over cyberspying and is embroiled in longstanding territorial rows in the East China Sea with Japan, and in the South China Sea with several regional countries.

- 'Very vague' -

Maya Wang, China researcher for US-based Human Rights Watch, said all governments were justified in having their own national security laws and apparatus, but the content of China's law had caused concern.

"It includes elements that define criticism of the government as a form of subversion," she said.

"It is very vague in defining what kind of specific actions would constitute a citizen endangering state security."

The new law has been also criticised by the European Union Chamber of Commerce in China, whose president Joerg Wuttke said in an emailed statement: "The definitions... are so extensive in both wording and scope that we are in effect looking at a massive national security overreach.

"Such vagueness creates a great deal of uncertainty for business."

Wang said the measure was part of a series of state security legislation -- including a new anti-terrorism law -- that as a whole "reduces the capacity of civil society to criticise the government and hold the government accountable".

Campaigners say the draft anti-terror law contains measures for a "non-stop strike hard campaign" in Xinjiang, homeland of the Uighur ethnic minority, signalling that a crackdown initially intended to last one year could continue indefinitely.

China has already rolled out tough measures to confront what it labels "terrorism" in the far-western region.

A new criminal law was submitted last week to the NPC, which includes harsher punishments for those involved in "cults or superstitious activities", and widens the list of activities which can be defined as terrorism, state media said.

The new national security legislation does not apply to Hong Kong under the "one country, two systems" principle that gives the former British colony wide-ranging autonomy.

But it mentions the territory, along with Macau, and pro-democracy Hong Kong lawmaker Alan Leong told local broadcaster RTHK it "can be considered as giving pressure to Hong Kong" to enact its own security law.

A security bill put forward by the Hong Kong government in 2003 sparked a massive protest, with some 500,000 people taking to the streets, before authorities scrapped the measure.