A Good Samaritan who stopped to help a woman claiming she was stranded in Ottawa's rural east end ended up being beaten and robbed on an isolated road, police said Monday.

The man was driving along Innes Road around 5:30 p.m. Saturday when a woman flagged him down and told him her vehicle had broken down about a kilometre down O'Toole Road, but she didn't have a mobile phone to call for help.

The victim drove the woman to the vehicle, but when they arrived a man got out and approached him while the woman demanded the Good Samaritan's wallet.

When the victim resisted, the woman and man assaulted him and a third assailant joined in, police said. The suspects took money from the man's wallet before leaving in their vehicle. The victim was taken to hospital for treatment of injuries received during the beating.

Swarmings, robberies on the rise

This is the latest robbery in a string of recent incidents involving violence or the threat of violence, Ottawa police said.

There have been 121 reported swarmings in Ottawa in 2017 compared to 100 at this time last year. Personal robberies, which involve a single assailant, are up too, with 96 so far this year compared to 61 at this time in 2016.

"It's very violent," said Staff Sgt. Michael Haarbosch of the police service's robbery unit. "These are the ones where we see the most serious injuries."

The sudden rise in these incidents is perplexing, Haarbosch said, because both swarmings and personal robberies have been trending downward for several years.

Haarbosch said the latest case is particularly troubling because the victim was lured by someone claiming to be in distress.

"We've got a victim who tried to do a good deed and at the end of the day came away having been beat up and robbed of cash," he said.

Don't fight back, police warn

The female suspect in this case is described as a white woman in her early 30s with a thin or medium build and weighing about 130 pounds. Her hair was dirty blond, short and spiky, she had a mole on her face and spoke both English and French, police said.

The male suspect is about five-feet-six-inches tall with a muscular build and a brush cut. He's balding and spoke English, police said.

There's no description of the third suspect. Their vehicle was possibly a dark-coloured older model four-door sedan, which was very dirty, police said.

Ottawa police caution residents against fighting back if they become the victim of a personal robbery. Instead, victims should hand over what's demanded and contact police as quickly as possible.