China's ambassador to Papua New Guinea has lodged stern representation to the nation's government after violence targeting Chinese-run businesses escalated over the weekend in the south western Pacific country.

China's embassy has issued an alert for Chinese citizens living in the region or planning visits in the near future, reminding them to remain vigilant, Xinhua News Agency reports.

Wei Ruixing, China's ambassador, has contacted local security authorities, urging an immediate and comprehensive investigation into the unrest.

Squads of heavily armed police were called in to protect Chinese-run businesses in the country, the Australian Associated Press reported on Monday.

Looting and anti-Chinese violence started in the capital Port Moresby last Wednesday and continued over the weekend in the country's highlands and Madang Province on the northwest coast.

Papua New Guinea's national newspaper estimated damages at close to 250,000 kina (95,000 US dollars).

Port Moresby's Governor Powes Parkop blamed police for the outbreak of violence, saying the police probably tolerated a march protesting Asian invasion into local markets.

Zhou Hanbo, from the Chinese Embassy in Port Moresby, earlier told Papua New Guinea's 'Post Courier' newspaper that the Chinese government was "gravely concerned" about the violence.

(CRI May 19, 2009)