Gardaí have expressed concern about an increase in people being robbed at night on two of Dublin’s busiest night-economy streets.

Officers are investigating at least 21 incidents of robbery and theft in Harcourt Street and neighbouring Camden Street in the past five weeks.

The majority of cases remain unsolved, and there is concern about a lack of gardaí patrolling the two streets, which are home to many nightclubs and pubs.

“The priority in the south city for late-night policing seems to be Temple Bar, meaning gardaí have been diverted from patrolling these locations on occasion,” a source said.

“There is plenty of overtime on offer for gardaí at the moment for these patrols, but there is an issue at times about members taking this up for a variety of reasons.”

Of the 21 incidents on Harcourt Street and Camden Street, five were robberies and 16 thefts from the person.

Two robberies were described as “extremely violent” and were carried out by two women on two men on July 30.

One of the victims in the separate incidents was an English tourist. An hour after he was robbed in the early morning, a Dublin-based man in his 20s was also targeted.

Both men suffered facial injuries and their mobile phones were stolen after they were directed away from Harcourt Street and Camden Place respectively by the women who assaulted them.

Gardaí believe the women have been working for a gang.

On the night of the two attacks, it is believed they stalked the streets for several hours looking for potential victims before approaching them and asking for directions.

Investigations have established that a car has been parked in lane-ways to which the suspects go with stolen goods.

It is unclear how many other robberies they have been involved in, but gardaí have obtained CCTV of them.

Public safety and garda resources on the streets of Dublin city centre have been the subject of much debate after a group of English tourists were assaulted and robbed in Temple Bar last weekend.

A 17-year-old west Dublin male has been charged in relation to the incident, and more arrests are expected in the coming days. Bail conditions include that he stay out of Dublin 2.

Following another violent street attack in the south of the city, a video has emerged of an incident at 6pm on Monday when a group of youths armed with bars and bats attacked a man near the Guinness Storehouse.

That case is being investigated as “a public order incident involving a large number of youths”.