Police in Hong Kong have arrested a man suspected of carrying out an acid attack that injured 30 people.

The man was detained after being spotted on a rooftop near the scene of Saturday’s attack on a night market in the Kowloon area, a spokesman said.

Nine tourists and a seven-year-old were among those treated in hospital.

More than 100 people have been injured since December 2008 in similar attacks in which bottles of acid were dropped from buildings in a pedestrian zone.

The man arrested over the latest incident was found hiding on a roof near Temple Street night market in Yau Ma Tei, with lids that fitted the bottles thrown, a police spokesman said.

It is not known yet whether the suspect has been linked to other attacks

Police have not said whether the man, who was described as being Chinese and in his 30s, is suspected of involvement in other attacks.

Hong Kong leader Donald Tsang condemned Saturday’s attack as “an outrageous and heart-breaking incident”.

He said the authorities were offering a reward of HK$300,000 ($39,000; £24,000) for information on the case.

Until now, the police have had little success in finding what is thought to be a lone perpetrator, the BBC’s Angharad Law in Hong Kong says.

In December, six people were injured when a bottle of acid was thrown down a street in Causeway Bay, a shopping hub which was packed with people celebrating the Hong Kong football team’s victory over Japan in the East Asian Games final.

Three other attacks have taken place in Mong Kok, a densely populated shopping area near the scene of the latest incident.