The three men, from Xinjiang, were waving long knives and chanting jihadist slogans when police opened fire at a rental home in a downtown area on Monday, the police bureau said.
The officers also arrested a 28-year-old woman, a Uygur from Xinjiang, who was injured in the shooting.
Police said more than 200 armed officers had been sent to the rental home to subdue the four, who were suspected of involvement in a “terrorist case” on June 12. A police statement did not say what the case involved, but said that in the past month 16 people had been arrested in connection with it.
Xinjiang authorities said in May they had broken up 181 terrorist groups over the past year.
The development came as a senior police official said poor intelligence and porous borders with Southeast Asia were hindering China’s efforts to stop the flow of ethnic minority Uygur Muslims heading to Turkey, where many go before joining up with Islamists in Iraq and Syria.
Hundreds, perhaps thousands, of Uygurs keen to escape strife in their far western Chinese homeland of Xinjiang have travelled clandestinely via Southeast Asia to Turkey.
Tong Bishan, a senior police officer who has been helping lead China’s efforts to get the Uygurs back, said that the Uygurs were mostly crossing into Vietnam and Laos.
Tong said he believed the numbers escaping had fallen a lot, but that it was impossible to stop them totally.
“I’ve been to the front lines, to the border with Vietnam, it’s mountains and rivers,” he said. “In some places, the border is a little stream, two or three metres wide. Jump over and on the other side it’s Vietnam. There’s no fence or anything.”