BEIJING (AFP) - A Chinese headmaster denied an explosion outside his primary school which killed two people and injured 44 others was the result of a feud involving him, media said on Tuesday.

Many children were among those hurt in the blast, which happened when a man rode a motorcycle past the school gate in Guilin as they arrived for classes on Monday.

The cause of the explosion was not clear, but early reports suggested the motorcycle caught fire before a "loud bang" was heard.

"Some media said the cause of the explosion could be somebody being involved with a feud with the school principal, who took his retaliation to extremes," said the People's Daily, the mouthpiece of China's ruling Communist party.

"Yesterday, the principal Qin Zhuanhong denied the claim, saying he had very few enemies and he does not know the blast site tricycle driver."

Officials in the southern city, in the Guangxi Zhuang Autonomous Region, also said reports that the principal was involved in a feud were "simply rumours" that police had not confirmed, the newspaper said.

Pictures posted online showed the mangled remains of a three wheeled motorcycle on the ground outside the school and another two wheeled vehicle in flames, with several people sitting on the ground bleeding.

A local official in Lingchaun county, where the explosion occurred, confirmed the death toll to AFP without offering further details.

Police in Guilin have begun a search for illegal explosives in the city, Xinhua said.