The commander of Canada's Air Force expressed his sympathies to the families of two women recently murdered near Belleville, Ont., and said he was "shocked" that a colonel under his authority has been charged with their murders.

"Their families have our deepest sympathy, as we ourselves mourn," Maj. Gen. Yvan Blondin told reporters at a news conference Monday.

The commander of CFB Trenton, 46-year-old Col. Russell Williams, was formally charged on Monday with murdering two women and sexually assaulting another two.

Bellville resident Jessica Lloyd, 27, went missing on Jan. 28. Her body was discovered on Monday. Marie Comeau, a corporal at CFB Trenton who lived in Brighton, Ont., was found dead in her home in late November.

Williams was arrested in Ottawa on Sunday in connection with their murders. He also stands accused of breaking into the homes of two other women and sexually assaulting them.

On Monday he was taken to a Belleville courthouse, wearing a blue prison suit as well as hand and leg shackles. He told the court he understood the charges that were laid against him.

Williams was then remanded to police custody until his next court appearance, which will take place by video on Feb. 18.

"We're shocked by the connection to a leader in our Air Force," Blondin said, adding that he could not comment on any aspect of the investigation.

An interim base commander has been appointed to take over Williams' responsibilities, Blondin added, so that personnel can continue to carry out their work at the base, which includes airlifts to and from Haiti and Afghanistan.

Police are combing through Williams' home in Tweed, Ont., about 30 kilometres north of Belleville. Trenton is about 18 km west of Belleville, and Brighton is about 15 km west of Trenton.

The suspect came to the attention of police following a Highway 37 roadside canvass on Thursday (Highway 37 runs from Belleville to Tweed). The investigation involved the OPP, Belleville Police and investigators from the Canadian Forces.

Det. Insp. Chris Nicholas told the news conference that the investigation caused police to examine other incidents in the surrounding area, including recent home invasions.

"Due to the seriousness of those incidents, the police linked the crimes to a single suspect," he said.

Police announced that Williams has been charged with two counts of first-degree murder along with two counts of forcible confinement and two counts of break and enter and sexual assault.

Those "home invasion" crimes occurred in the Tweed area in September, Nicholas said.

Earlier Monday, police were seen cordoning off a property on Cosy Cove Lane in Tweed, a site that is reportedly close to where Lloyd's body was found. The registered owner of the home is listed as Col. Russ Williams.

Police say their investigation will extend to other communities Williams lived in recent years. As a career military officer, he moved around a lot.

Williams joined the Air Force in 1987 and rose through the ranks. Before becoming a base commander in July 2009, Williams -- who is married, according to his Canadian Forces biography -- piloted the Challenger aircraft that is often used by Canada's elite dignitaries.

From December 2005 to June 2006, he reportedly commanded Camp Mirage, a secretive logistics base reportedly near Dubai that's not officially acknowledged by the government or military.

One photo shows him with Defence Minister Peter MacKay and Gen. Walter Natynczyk, chief of the defence staff.

No allegations against Williams have been proven in a court of law.

Lloyd was last heard from on Jan. 28, when someone sent a text message from her cellphone to a family friend. Police say she was last known to be at her home on Highway 37 in the late hours of that same evening.

Her family reported her missing the next day after she failed to show up for work at Tri-Board Student Transportation Services in Napanee, Ont.

In the days that followed, police launched helicopter and ground searches but did not locate her.

With a report from CTV's John Vennavally-Rao and files from The Canadian Press