Winnipeg police say they have detained a man in connection with a bomb that detonated inside a law firm Friday, leaving a woman with "extensive injuries."

At a press conference on Sunday, Supt. Danny Smyth said the 49-year-old suspect was taken into custody on Saturday evening after he was apprehended at his residence.

Authorities have a 24-hour window before charges must be laid.

On Friday, police responded to reports of an explosion at Petersen King law firm on River Avenue in Winnipeg.

Lawyer Maria Mitousis, 38, was rushed to hospital in critical condition after the blast.

Smyth said Mitousis suffered "extensive upper-body injuries" but has been "stabilized" and remains in hospital.

"I expect her recovery will take a considerable time," said Smyth.

Mitousis' colleagues have set up a GoFundMe page to help cover expenses related to her recovery. As of Sunday night, the page had raised nearly $15,000.

"We invite the legal community and the community at large to work with us to offer Maria continued support as she recovers from this horrific and life-altering event," Laurelle Harris and Kelli Potter wrote in a description on the page.

Investigators said they believe the attack was targeted and there is no "blanketed threat" to the public.

Smyth said the blast on Friday was also connected to another bomb threat at a business at the 500 block of Washington Avenue on Saturday.

"I know (investigators) have made a solid link ... but I'm really not prepared to get into that detail right now," Smyth said.

A bomb unit was sent to the location and confirmed that there was an explosive device at the scene.

"Steps were taken to neutralize the device with use of a water cannon, which ultimately detonated the device," Smyth said.

Police said there were no injuries but there was "extensive" damage to the business.

Smyth added that investigators were able to speak to Mitousis in hospital.

"I don’t know how extensive it was … she's been through a lot in the last couple of days and I understand she's had surgery, but certainly we were able to clarify some things with her," Smyth said.

Police have not yet determined whether she or other workers in the law firm were the targets.

Friday's bombing happened just days after Mitousis' boyfriend, Barry Gorlick, was stripped of his licence to practice law.

Police said they are aware that Gorlick, who worked at another firm, pleaded guilty to misappropriating money from two clients and lying to a third. However, they have not linked Gorlick to the two incidents.

The explosion also prompted the Law Society of Manitoba to warn its members about suspicious packages.

The investigation is ongoing and search warrants are being executed.

Police remain on scene at two locations: a business on Springfield Road and a residence on Pandora Avenue.

Some residents near the Pandora Avenue residence have been evacuated as a precaution. However, police are not aware of any specific information regarding explosive devices at either location.

Police have dealt with more than a dozen calls about suspicious packages over the weekend, but most were harmless.

With files from The Canadian Press