OTTAWA - The RCMP's national security team has arrested and charged a third Ottawa man allegedly linked to the twin brothers arrested last weekend on terror charges.

The Mounties announced Monday that its integrated national security team arrested Suliman Mohamed, 21, and has charged him with participating in the activity of a terrorist group and conspiracy to participate in a terrorist activity with Ashton and Carlos Larmond.

While the allegations were not detailed by the RCMP in a news release, the charges appear serious carrying jail terms of, in the first instance, up to 10 years, and in the second, up to life in prison.

After a months-long investigation, the Larmond brothers, aged 24, were arrested separately Friday. Mounties picked up Carlos Larmond at Montreal's Pierre Elliott Trudeau International Airport, and Ashton Larmond was reportedly arrested at a local ski hill. The two lived in the east-end Vanier neighbourhood and are now detained at the Ottawa-Carleton Regional Detention Centre.

Lawyer Joseph Addelman, who has represented both brothers in the past, said the charges date back to August 2013. At court in Ottawa on Saturday, he said his clients intend to "vigorously defend" themselves against the allegations.

In a news release Monday, the RCMP thanked Ottawa Police and OPP "for their vital contribution" in the investigation.

RCMP Chief Supt. Jennifer Strachan, Criminal Operations Officer for the RCMP in Ontario stated: "These recent arrests underscore the reality that there are individuals in Ontario and in Canada who have become radicalized to a violent ideology, and who are willing to act upon it. Thanks to the ongoing collaborative efforts of our INSET partners, we are in a better position to target these threats and protect the Canadian public."

"As this matter is now before the courts, we will not be providing more details at this time," the release stated.

- Ottawa twins plan to 'vigorously defend' themselves against terrorism charges

- RCMP arrest two Ottawa men on terrorism charges