The Manitoba government is beefing up security for justice workers after four masked men attempted to break into a senior Crown attorney's home.

Police said the unidentified lawyer received a threatening phone call at her office last Friday. The next morning, just after 6 a.m., four armed intruders threatened to harm her as they tried breaking into her home.

Her husband told CTV Winnipeg he fought back, while the noise attracted neighbours who called police.

"A neighbour saw four men wearing balaclavas get out of van and head for the house. They were carrying knives and actually got into the porch ... at the back" of the house, said CTV Winnipeg's Crimewatch reporter Kelly Dehn. However, the intruders "scattered before officers could arrive on the scene."

Hours later, police arrested three men who face charges including break and enter and uttering threats. Police were still searching for a fourth man Monday.

The woman's husband says he has no idea why they were targetted.

But police said they were also investigating whether the crime may be linked to any recent prosecutions led by the lawyer.

On Friday, a man hurled obscenities at the prosecutor after he was sentenced to five years for a robbery. Shortly after, the prosecutor received the threatening call.

"We don't know if it is connected at this point," police spokesperson Const. Jacqueline Chaput told CTV on Monday.

The province said it is launching a review of its security measures and making some immediate improvements, although Manitoba's Attorney General Dave Chomiak would not reveal details.

"We do provide a wide range of (security) services based on risk analysis,'' Chomiak told the Canadian Press."What we are doing immediately is expanding the perimeter or the types of security to a broader range.''

Meanwhile, the threats and attempted break-in shocked Winnipeg's legal community -- with some calling it an attack on the justice system itself.

"Most people in the criminal justice system, most of my clients realize the prosecutor's only doing their job," lawyer Jay Prober told CTV Winnipeg.

Assistant Deputy Attorney General Don Slough said prosecutors do receive threats occasionally, but in this case, "the apparent follow through . . . is something different -- and that's very concerning."

Slough said Crown lawyers have previously expressed concerns about their safety in contract negotiations with the government.

Security steps to protect the prosecutor were taken after the initial threatening phone call was made, but she was not placed in police protection.

"What we knew at the time wouldn't have warranted police protection. That isn't where we were headed," said Slough.

Chomiak said the prosecutor is doing as well as could be expected under the circumstances.

"I've talked to the individual involved and that person is a strong person. The system of justice and the people in it are a lot stronger than those elements out there that seek to take advantage of the system,'' he said.

Charged are Alphonse Stanley Traverse, 27; Gerald Wayne Duck, 19; and Colin Leonard Traverse, 23.

Police issued a warrant for Phillip Wesley Trout, 21.

With reports from CTV Winnipeg's Kelly Dehn and the Canadian Press