A postsecondary student has been arrested after being caught with two petrol bombs outside a Hong Kong police station. The 21-year-old man, a student at the Hong Kong Institute of Vocational Education, was spotted acting suspiciously in Kwai Chung on Monday evening, and was subsequently found to be in possession of the bombs, a police source said on Tuesday. Officers had placed the student under surveillance after spotting him at Kwai Fong Estate in Kwai Chung shortly after 8pm. One police source said the man was found wandering around the rest area in Kwai Foo Road, which is opposite Kwai Chung Police Station. “He then left a bag on a table. Officers moved in and intercepted him when he was about to leave. Officers found two petrol bombs inside the bag,” the source said. Police believe the suspect was responsible for carrying the petrol bombs to the site for his accomplices to use in an attack on the police station. As of Tuesday afternoon, officers were still searching for a car that drove the suspect to the Kwai Fong Estate. Police arrested the man for possessing an offensive weapon. He was being held for questioning and had not been charged. There have been a spate of petrol bomb attacks against police stations in the city over the past three months. In January, three black-clad men launched a firebomb attack against Kwai Chung Police Station . One of the three petrol bombs was hurled into the entrance of the station’s car park, and the other two landed in Kwai Foo Road. No one was injured in the incident. On March 30, three petrol bombs were hurled into Happy Valley Police Station . Police are still searching for three suspects in connection with the case. And three schoolboys aged 16 to 18, were arrested after five petrol bombs were thrown into Tai Po Police Station on April 1. In the first three months of this year, there had been 16 firebomb attacks involving 71 petrol bombs against police buildings, including staff quarters. Security around police stations and living quarters for officers has been enhanced since January, after a message which read “burn doghouse” was posted on Telegram, an app used by anti-government protesters who use the term “doghouse” to refer to officers’ homes and police stations. Police figures show the number of juveniles aged 10 to 15 arrested rose 22.8 per cent in 2019, to 1,140, up from 928 the year before. Arrests for criminal offences among those aged 16 to 20 jumped even more dramatically for the same period, with 3,128 arrested, up 69.9 per cent from 1,841 in 2018. Police said most of the crimes committed by youths were offences against public order such as unlawful assemblies and riots tied to the citywide social unrest that first erupted in June.