Hong Kong, Dec 12 (IANS): Police were hunting for six suspects after petrol bombs were hurled at a Hong Kong metro station on Thursday, forcing the rail operator to immediately evacuate the area and close the site.

The incident came just hours after police arrested a 29-year-old man and two teenagers in separate incidents, reports the South China Morning Post newspaper.

The Mass Transit Railway (MTR) Corporation said black-clad "rioters" hurled petrol bombs at two escalators and a shop at the Ngau Tau Kok station in Kowloon at around 1 a.m.

They also vandalised ticket machines and other facilities on the concourse.

The suspects fled before police arrived, no one was injured, and rail services resumed later in the day.

The last petrol bomb attack on the city's rail network was on December 1 in Whampoa, when protests turned ugly after thousands marched from Tsim Sha Tsui harbourfront to Hung Hom.

The rail operator emerged as a key target for radicals in August, two months after the anti-government protests broke out, after they accused it of bowing to pressure from Beijing following a scathing attack by mainland media.

As of November 24, radicals had caused extensive damage to 85 of 94 MTR stations.

Affected facilities include ticketing machines, surveillance cameras, lifts and escalators and rolling shutters.