BEIJING — China needs to be more candid about the nature and causes of recent incidents of deadly ethnic violence in the northwestern region of Xinjiang, the European Union's ambassador to Beijing said Monday.

The EU appreciates China's efforts to develop the region but "we do believe it is necessary to address the underlying causes of ethnic tensions in order to achieve lasting stability and prosperity," Markus Ederer told reporters at a briefing.

"We are concerned by the lack of transparency when it comes to the reporting about what happened. We believe that transparency would help to make clear the amount and the source of this violence," Ederer said.

Bordering Central Asia, Afghanistan and Pakistan, Xinjiang (shihn-jeeahng) has long been home to a simmering rebellion against Chinese rule among parts of the Uighur (WEE'-gur) population opposed to large-scale migration by China's Han majority and angered by strict communist restrictions on their Muslim religion and Turkic language and cultural institutions.

Violence appears to be rising, however, and recent incidents appear to point to the growing influence of radical Islam, in spite of a massive security presence spread across the vast region.

Chinese paramilitary troops have been ordered to conduct round-the-clock patrols following a series of bloody clashes that have killed at least 56 people over the last several months. The order issued Saturday comes days ahead of the July 5 anniversary of a 2009 riot in the regional capital Urumqi that left almost 200 people dead, most of them Han civilians.

Areas where clashes have occurred have been sealed off and information about them has been tightly controlled. Beijing has mainly blamed the attacks on violent Muslim extremists inspired by jihadist literature smuggled over the border or downloaded from the Internet.

Beijing says it treats the country's minority groups fairly and that it has poured billions of dollars into raising living standards in Xinjiang.

Four years after the 2009 riot, security remains heavy across the region that is more than twice the size of Texas. Resentment over oppressive policies among Uighurs is a main cause of the recent violence, said Germany-based Uighur activist Dilxat Raxit.

"People are still living in the shadow of the July 5 violence. It's painful for families whose sons and fathers have been rounded up with no concern for their human rights," Raxit said, referring to frequent reports of Uighur men detained in security sweeps.

In the bloodiest recent incident, 35 people were killed last week when a group of assailants attacked a police station and government offices in the eastern Xinjiang town of Lukqun.

Following that, the United States State Department urged Chinese authorities to conduct a transparent investigation, and expressed concerns that Uighurs were suffering from discrimination and restrictive policies.

Such statements are met by Beijing with accusations that the West maintains a double standard when it comes to dealing with terrorism.

"The biased prism through which some U.S. politicians view such horrible acts, means that if it happens in the United States or harms U.S. citizens it is a terrorist attack, but when it happens in other countries it is viewed as something else," the official English-language newspaper China Daily said in a Monday editorial.