HONG KONG: A witness who claims to have seen a suspicious man run out from a building on Nelson Street in Mong Kok shortly after the latest acid attack is helping police with their investigation.

The incident on Monday evening - the third such case since December - left 24 people injured by a bottle of suspected corrosive acid hurled down from a building nearby.

A worker at a bookstore on Nelson Street told police that he had seen someone running out from a block nearby soon after the incident. "He seemed not nervous at all. He wore a pair of black-framed glasses, a black and white striped shirt, a pair of black trousers and a rucksack," he said.

Police will cordon off a section of Nelson Street this morning to carry out a re-enactment of Monday's attack.

Secretary for Security Ambrose Lee Siu-kwong said the authorities will put the data they have collected into its "supercomputer" to see if there is any linkage among the recent spate of acid attacks.

Speaking at the Legislative Council, he said police had stepped up patrols in Mong Kok and officers are monitoring the busy shopping district from high vantage points in an effort to prevent any repeat of the acid attacks.

Lee said the authorities are still unclear about the motives for the three acid attacks.

He said some suggested that the attacker or attackers were annoyed about the noise level in the pedestrian area of Mong Kok while some suggested the incidents might be related to triad gangs who were upset about recent police crackdowns on brothels. He said the police have not ruled out any possibility.

He said such cases were tough to crack as the attacker or attackers are seldom witnessed committing the offence, and the perpetrator or perpetrators usually have no connection with the victims.

Lee said the authorities are doing their best to catch the attacker or attackers and urged the public to give them time and provide information.

Police will continue to carry out door-to-door surveys on households and shops nearby and try to find more witnesses, he said.

Five of the victims of Monday's attack were tourists from the Philippines. The five victims, along with their families, were admitted to Disneyland for free yesterday.

Debbie, one of the Filipino tourists, said: "We were all shocked about what happened. We couldn't imagine that it actually happened to us."

She said she felt unhappy about the incident but might visit Hong Kong again in the near future.

A reward of HK$900,000 is on offer for information leading to the arrest of the person or people responsible for the recent attacks.

(HK Edition 06/11/2009 page1)