Two armed robbers wielding a sledgehammer stole HK$3 million (US$383,000) worth of valuables from a Hong Kong jewellery store in a daring daylight raid on Monday – the second robbery of its kind in the city in less than 24 hours.

A police source said officers were investigating if the two cases were linked, and whether the same gang also struck in an armed robbery in November, when HK$2.5 million in jewellery and cash was taken from a shop in Tsuen Wan.

The latest robbery occurred at about 11am, when two suspects carrying a knife and a sledgehammer ran into the Fook Tai store on Castle Peak Road in Sham Shui Po.

“The two men used a hammer to smash the glass on the display counters and snatched jewellery before they fled in a white car,” a police spokeswoman said.

Officers said the getaway car was driven by a third man. According to police, the three black-clad suspects were wearing caps and face masks at the time of the robbery.

The sledgehammer used by the robbers was found inside the shop, where glass fragments were scattered on the floor along with several gold ornaments. As of 6pm, no one had been arrested in connection with the case.

On Sunday, four masked robbers smashed the glass cabinets at a jewellery shop in To Kwa Wan and grabbed HK$2 million worth of gold items before fleeing in a taxi driven by an accomplice at about 3.40pm.

According to the force, there was almost one robbery case per day in October, up from one report every two to three days on average in 2018.

Chief Superintendent Kenneth Kwok Ka-chuen, head of the Police Public Relations Branch, said officers did “not rule out the possibility some criminals are taking advantage of ongoing social unrest to carry out robberies”, with a lot of police resources tied up dealing with anti-government protests which have gripped the city for nearly six months.

Since August, Hong Kong police have stopped patrolling city streets on foot because of a lack of available officers, as well as the perceived risk of attacks by protesters. Officers are now patrolling in police vans instead.

On November 17, a similar robbery happened in Tsuen Wan, when four robbers threatened the shop’s employees with a knife and what appeared to be a handgun, smashed a glass cabinet and fled with HK$2.5 million in jewellery and cash.

In 2017 and 2018 there were a number of high-profile smash-and-grab robberies that prompted local jewellery and goldsmith shops to enhance security.

In September 2017, three thieves fled on a motorbike with HK$24 million worth of jewellery after smashing a store window with hammers at a Canton Road jewellery shop in the busy shopping district of Tsim Sha Tsui.

In March 2018, police arrested three tourists from Colombia after they made off with HK$40 million worth of jewellery in a smash-and-grab robbery in Central.

Last month, there were three robberies in Tsim Sha Tsui and nearby Yau Ma Tei within three weeks.

On November 27, three masked men attacked a man and his female relative and snatched her bag containing HK$1.2 million in Ashley Road, Tsim Sha Tsui.

Seven days before, a gang of six men attacked three mainland men and snatched their suitcase containing HK$15 million in Minden Avenue, Tsim Sha Tsui. On November 8, four robbers made off with HK$10 million worth of watches from a shop on Kwong Wah Street, Yau Ma Tei after one of the suspects threatened a male employee with a knife.