TOKYO — Two Japanese journalists were briefly detained and beaten by police in western China, their companies and one of the men said Tuesday, triggering a protest by the Japanese government. Chinese officials later apologized.

They were working in Xinjiang at the scene of a deadly attack Monday on Chinese policemen when they were forcibly taken to a border police facility, said Shinji Katsuta, a reporter for Japanese broadcaster Nippon Television Network Corp.

"My face was pushed into the ground, my arm was twisted and I was hit two or three times in the face," he said in a phone interview broadcast on his station.

A photographer from the Tokyo Shimbun newspaper, Shinzou Kawakita, was also apprehended and roughed up, said a company spokesman who declined to give his name, citing company policy.

The incident, which Katsuta said also involved several reporters from other countries, occurred just four days before the Beijing Olympics' opening ceremony on Friday.

The men were held for about two hours, then taken to their hotel and questioned by local authorities before being released early Tuesday morning. Later Tuesday, local officials apologized for the incident to them and other foreign reporters that had also been involved, a spokesman at their companies said.

Katsuta had no serious injuries and planned to continue working in Xinjiang, said Nippon Television spokesman Kenji Chikata. He said the company also plans to file a complaint with the Chinese Embassy in Tokyo.

The Tokyo Shimbun spokesman couldn't immediately confirm Kawakita's condition.

Japan's Chief Cabinet Secretary Nobutaka Machimura, the country's top spokesman, told reporters at a regular press conference that Tokyo plans to "lodge a strong protest" with Beijing over the incident.

The reporters were in Xinjiang to report on an attack by two men from a mainly Muslim ethnic group, who rammed a truck and hurled explosives at jogging policemen Monday, killing 16. It was the most brazen and deadly attack in China's restive far west in years.

Chinese authorities have promised freedom for foreign news organizations in the country during the Olympics. But many have met with problems, including authorities cutting off live broadcasts, restrictions on reporters' movement and coverage, and Internet censorship imposed on journalists.