A total of 18 people were killed during an assault on a Chinese police station in the restive western province of Xinjiang on Monday, including 14 Muslim Uighur attackers who were shot by police, state media said Wednesday.

In the first detailed accounting of the incident, the Xinjiang government’s news Web site and Xinhua, the official Chinese news agency, said an armed policeman, a security guard and two civilian hostages — a woman and a teenage girl — were killed when the Uighurs stormed the station.

The reports said that three other civilians were injured, four attackers were captured and six hostages were freed.

However, the Germany-based exile group representing the Uighur community, the World Uighur Congress, offered a different version of events.

The group said Uighur protesters were trying to rally at the police station in support of people detained inside when the police opened fire on them. The group’s spokesman, Dilxat Raxit, said by telephone that 20 Uighurs were killed, and he called for an independent investigation.

The attack, which began at noon Monday in the desert city of Hotan, near the Pakistan border, marked the most serious eruption of violence recorded in the province since ethnic rioting in July 2009 left nearly 200 people dead and scores of shops and businesses burned.

State media said the attackers in Monday’s incident, described as “rioters,” stormed the police station armed with axes, knives, daggers, Molotov cocktails and other explosives.

The report on the Xinjiang Web site said the attackers “beat, smashed and burned crazily,” shouted slogans invoking “Allah” and hung a separatist flag on top of the station.

The Web site said the attack happened at a time when most of the police officers were absent on a mission. The security guard left behind was hacked to death, it said.

Raxit, the Uighur exile group’s spokesman, sharply disputed the official accounts. He said the incident began when people gathered at Hotan’s grand bazaar for a planned protest. Police broke up the rally, and 13 Uighurs were arrested. Raxit said the angry protesters then moved to the police station and a commercial office next door.

“There was violence, but it was caused by the government’s crackdown,” Raxit said. He said some of the dead and injured Uighurs were taken away in military vehicles to a military hospital.

After the incident, Raxit said, Chinese security forces were examining people’s cellphones to make sure no video of the incident could be released on the Internet.

The Turkic-speaking Uighurs consider Xinjiang their traditional homeland, but large influxes of ethnic Han Chinese over the years have left them a minority. The Uighurs complain that they are economically disadvantaged and that Chinese security forces impose security in their communities with a heavy hand, including mass arrests.

Hou Hanmin, deputy director of the local information department, said the exile group’s account was “totally fake and not true at all.”

“There was not any protest or conflict that happened before the attack,” she said. She said some of the surviving attackers admitted under questioning to carrying out a planned attack on the police station. She said some of the attackers were from outside Hotan.

“They shouted extremist religious slogans and hung an extremist religious flag,” Hou said. “Compared with past attacks, these were more religious fanatics. It’s a new characteristic.”

Staff researcher Zhang Jie in Beijing contributed to this report.