SHANGHAI, CHINA (AFP) - Shanghai's National Business Daily said an editor and several journalists were attacked Friday by men claiming to work for a shampoo maker whose products have been alleged to contain toxic chemicals.

The newspaper's spokeswoman Xu Yuanyuan said police detained a man claiming to be a sales manager for BaWang International and three others after the attack at the newspapers' office.

Calls to police went unanswered when AFP tried to confirm the detentions. BaWang officials were also unavailable for comment.

The four men had demanded to see the newspaper's editor and the reporter who wrote about a government investigation into the company's shampoo, Xu said.

The men began punching the glass doors in the offices reception area as the editor spoke to them and the situation escalated as journalists took photos of them, Xu said. A scuffle broke out involving several journalists.

"Companies that act out of vengeance over media reports should be condemned," Xu said, adding that no one was seriously injured.

The man, surnamed Hong, allegedly confirmed to police that he worked for BaWang but the three others remained unidentified, according to Xu.

Hong Kong-listed BaWang saw its shares slump after the Hong Kong-based Next magazine alleged tests had shown some of its shampoo products contained the cancer-causing chemical dioxane.

The company, based in Guangzhou city in southern China, responded to the reports by saying its products were safe.

China's State Food and Drug Administration issued tests saying the dioxane levels in BaWang's shampoo would not hurt consumers' health.

The incident was the latest showdown between companies unhappy with reports and journalists from the Chinese media, who are becoming increasingly aggressive in exposing corporate and official malfeasance despite government censorship.

Police in eastern China on Thursday quashed an arrest order for a fugitive graft-busting journalist following a public outcry, in an apparent rare victory for media freedom.