Police arrested a man early today after acid was thrown down onto shoppers in one of the city's top tourist spots, the Temple Street night market, injuring 30 people, several of them tourists. The arrest could mark a significant breakthrough in the police hunt for the perpetrator of five acid attacks over the previous 13 months which left more than 100 people injured. Yau Tsim District police commander Lau Yip Shing said the suspect in detention, a Chinese man in his 30s, was arrested on the rooftop of a building next to the scene of last night's attack after police found lids that fitted the two bottles used in the attack. He was hooded, handcuffed and put into a private car by police. Officers were investigating whether he was involved in the attack and will continue to scour the scene for evidence later today. The attack happened at about 9.30pm. The two bottles of corrosive liquid were thrown into the night market. The 30 injured suffered chemical burns. Restaurant staff gave water to the injured to wash their wounds before paramedics arrived to give them initial treatment. Most of those hurt sustained injures to their heads and eyes. Lau said children and nine tourists were among the injured. The youngest victim was seven, the oldest 56. The victims were sent to the Queen Elizabeth and Kwong Wah hospitals for treatment. None was seriously hurt and all were discharged last night after receiving treatment. Lau said police had yet to determine the motive of the perpetrator and did not rule out links with the previous acid attacks. Lau said the attacker was a disgrace. Asked whether the attacker was challenging the police, Lau said: 'The attacker is challenging society.' A Malaysian tourist who was having dinner at a ground floor restaurant at the time of the attack said many people were eating outdoors. 'People were running for shelter and some were screaming. It was chaotic,' she said. She saw an injured woman with blisters on her face, neck and ears grimacing. The operator of a store opposite the scene of the attack, at the junction of Nanking Street and Temple Street, Yau Ma Tei, said he heard two bangs during the attack. 'The first bang was louder. It was followed by another, softer bang. Soon after that there was a pungent smell. Then I knew that it was another acid attack. I stayed in my stall and about 20 others rushed into the stall for shelter. Some were crying, others were screaming.' He said because it was a Saturday night, there were many tourists. Temple Street is the city's busiest night market. Sometimes called the Men's Market, it is listed in all popular tourists guides to Hong Kong as a must-see attraction. Following the attack, the two bottles used were found in front of a convenience store and a stall. Lau, the police commander, urged anyone who saw anyone acting suspiciously at the time of the attack to call police on 2761 2401. Police received a report of the attack at 9.35pm. Residents in the area blocked the exits of buildings near the scene before police arrived. Hundreds of officers combed the area for any sign of the attacker or evidence of his movements. There are many tenement buildings in the area with no security guards watching who comes and goes, and the entrances and doors to the rooftops are not locked. 'Eye in the sky' surveillance cameras were installed overlooking the Mong Kok pedestrian precinct where three of the acid attacks occurred, including the first more than a year ago, but they do not cover Temple Street. All the acid attacks have involved bottles of corrosive liquid being thrown from buildings into pedestrians areas. Most occurred on busy evenings. Despite thousands of hours of detective work, HK$900,000 in rewards and the installation of the surveillance cameras at a cost of HK$1.7 million, police still do not know the identity or motive of the attacker or attackers. Surveillance systems are being considered for other shopping zones. Criminologists believe the attacker is a lone male who is daring police to catch him. The attacker is likely to be over 21 and agile enough to escape quickly. The first attack occurred in Mong Kok on December 13, 2008. Two subsequent attacks, in May and June, also occurred in the same area. In October, an attack occurred in Sham Shui Po but no one was injured. Last month, an attack in Causeway Bay left six people hurt, two seriously.