BEIJING, China (CNN) -- Chinese paramilitary police beat two Japanese journalists Monday night in the border city of Kashgar, where a deadly attack targeting police officers had occurred hours earlier, journalist groups said.
Paramilitary police detained Masami Kawakita, a photographer with the Chunichi newspaper, and Shinji Katsuta, a reporter with the Nippon Television Network, as they were covering the recent attack on police, the Foreign Correspondents Club of China and Reporters Without Borders said.
The police yanked them off the street, beat them and damaged their equipment, according to the two journalist groups -- which cited the journalists' employers, several witnesses, and the national Kyodo news service of Japan.
On Tuesday the police apologized to the journalists, the Foreign Correspondents Club of China said.
"It was unbelievable," Kawakita said, according to the correspondents club. "Imagine how I felt to be suddenly surrounded by paramilitaries."
The two were covering Monday's attack, which according to Chinese state-run Xinhua news agency killed 16 police officers and injured another 16. Watch a report on the significance of the attack »
After pulling them from the street, the police took Kawakita and Katsuta to an official hotel, said Reporters Without Borders, often known by its French title Reporters Sans Frontieres.
However, Suzuki Takayoshi, who heads Chunichi newspaper's China coverage, said police carried Kawakita into an armed police compound, holding his hands and feet.
Once inside, police pushed Kawakita to the ground and kicked him in his face and torso, Takayoshi said. They took away two cameras to check the photographs on them, Takayoshi said, returning them to him later. One camera was returned broken, Takayoshi said.
Police released Kawakita two hours later, Takayoshi said. Reporters Without Borders said Katsuta was released at the same time.
Reporters Without Borders said both men sustained minor injuries. Takayoshi said Kawakita had no serious external injuries, but is worried about fractures. Kawakita is returning to Beijing, Takayoshi said.
Takayoshi did not have any information about Katsuta, and CNN's attempts to reach Nippon Television Network were unsuccessful.
Takayoshi confirmed the report that the police had apologized.
They explained that they could not immediately identify Kawakita because of the language barrier, Takayoshi said. Furthermore, the police said they were angry and short-tempered due to Monday's attack.
Police have arrested two Uygur men, ages 28 and 33, in connection with Monday's attack, Xinhua said.
The Xinjiang Uygur Autonomous Region -- also called East Turkistan -- where Kashgar is located, is home to a Sunni Muslim ethnic minority.
Uygurs in Xinjiang are supposed to enjoy regional autonomy, as guaranteed by China's constitution, but some seek independence.
Millions of Han Chinese, the country's dominant ethnic group, have migrated into Xinjiang over the past 60 years, prompting complaints that they dominate local politics, culture and commerce at the Uygurs' expense.