In this file photograph dated Dec 6, 2019, a police officer wears a bomb suit during a media tour of the Hong Kong Police Explosive Ordnance Disposal Bureau (EOD) depot in Hong Kong. (PHILIP FONG / AFP)

HONG KONG - A suspected small-scale homemade bomb exploded at a general hospital in Hong Kong on Monday, causing the temporary evacuation of some patients but no injuries, police said.

The motive for exploding the device in a toilet cubicle at Caritas Medical Centre around 2.30 am local time is not known 

The incident happened after a group of protesters on Sunday set alight the lobby of a newly built residential building in Hong Kong that authorities had planned to use as a quarantine facility. Authorities later shelved the plan. 

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The device exploded in a toilet cubicle at the Caritas Medical Centre at about 2.30 am local time, police said in a statement. The explosive ordnance disposal unit "found a suspicious bomb inside a toilet, 15 cm long, 10 cm in diameter," police said. "They took away the pieces of the suspicious bomb for further examination and evacuated around 20 people to a safe place. No one was injured."

The motive for the hospital explosion was not known.

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Hong Kong on Sunday barred residents of China's Hubei province, the centre of the virus outbreak, from entering the city. Chief Executive Carrie Lam last week dismissed a border closure as inappropriate and impractical.

Hong Kong has so far confirmed eight cases of people infected with the virus, which has killed 80 people on the Chinese mainland.