Police snipers are seen deployed on the rooftop of a building during an anti-terror operation in Shenyang, Liaoning province, on July 13, 2015. Photo: weibo.com

Chinese police in the northeastern city of Shenyang shot dead three knife-wielding militants from northwestern China's Xinjiang Uyghur Autonomous Region and wounded another on Monday afternoon, state media reported.

The four masked people were waving long knives and shouting jihad slogans from the 10th floor of an apartment building on Dongshunchengnei Street, Shenhe district in Shenyang, capital of northeastern China's Liaoning province, and attempted to kill policemen who knocked on their door, according to a police statement posted by the Liaoning provincial government on its official Sina Weibo account.

The policemen called for back-up, including special weapons and tactics (SWAT) teams.

When two SWAT officers entered the apartment through the window, two of the suspects allegedly attacked the policemen with broadswords and the other two used "blunt tools".

The policemen fired at them at close range after warning them not to approach.

"I heard several gunshots from the residential building," an anonymous store owner told the Global Times on Monday.

"There were also many police cars and ambulances occupying the street," he said.

The state-run Beijing News and other Chinese media outlets, citing the Liaoning provincial government, said that three "accompanying children" and "another Uyghur woman" were apprehended. None of them were injured.

The statement from the Shenyang public security bureau said that no civilians were killed or wounded in the incident but gave no further details.

Police have not identified the suspects, and further investigation is being conducted.

Meantime, police arrested 16 people suspected of being involved in terror crimes in Shenhe district on Monday morning.

It was the latest incident in a provincial capital in China.

Shenyang is almost 3,000 kilometers from Urumqi, the capital of Xinjiang, which has seen sporadic violence in recent years blamed by Beijing on Islamist terrorists.

Hundreds have died in violence in Xinjiang. Beijing blames the unrest on Islamist militants and separatists who want to establish an independent state called East Turkestan for Uyghur people, who speak a Turkic language.

Last week, Thailand deported 109 Uyghur people to China last week, some of whom Chinese state media said were planning to go to Syria and Iraq to join Islamist militants fighting there.

Stringent crackdown

Clashes between the government and Islamist separatists - as well as attacks killing civilians - have spread in recent years, both in Xinjiang and outside it.

Beijing launched a stringent crackdown on terrorism in Xinjiang just over a year ago after an attack on a train station in Urumqi as Chinese President Xi Jinping was visiting the city.

China said in May that 181 violent terror gangs across the country had been busted as part of the "strike hard" campaign. Scores of people have been sentenced to death as part of the drive, while hundreds have been jailed or detained on terror-related offences.

Authorities have also targeted religious practices, such as the wearing of veils, which activists say has created an atmosphere of repression and led to violence.

China defends its policies, arguing that it has boosted economic development in the area and that it upholds minority and religious rights in a country with 56 recognized ethnic groups.