Toronto's deputy police chief asked for the public's help Tuesday in determining who built a mysterious tunnel near a major sporting venue and a university in Toronto, and why.

A wildlife official was walking through woods near York University and the Rexall Center last month when he spotted a piece of corrugated metal on the ground, lifted it up and found a passageway.

A baby died and four young siblings were in critical condition after they were accidentally exposed to bedbug fumigation chemicals at their western Canada home, police said Monday.

Corporal George Cameron of the Royal Canadian Mounted Police told Agence France Presse the children were rushed to the hospital Sunday after firefighters responded to a chemical spill in a home in Fort McMurray, about 400 kilometers (250 miles) north of Edmonton, Alberta.

Canadian privacy watchdogs warned Wednesday that cameras increasingly worn by police risk chipping away at legally-protected personal privacy.

Officers in Calgary recently became the first in Canada to wear the recording devices on their uniform while on patrol.

Canadian police warned in a leaked document Wednesday of growing threats to the country's oil industry by militant climate activists opposed to the use of fossil fuels.

Greenpeace called the year-old report obtained by Agence France-Presse "chilling," because of its broad-brush depiction of climate-change activists as potential extremists.

Canada announced Tuesday new sanctions against Moscow and its sympathizers, including the state oil giant Rosneft, as pro-Russian separatists defied a ceasefire and stormed a flashpoint town in eastern Ukraine.

Two months after sanctions took aim at Russian interests in its vital oil and gas sectors, Canada targeted a flagship of the Russian economy in Rosneft.

The cost of Canada's six-month bombing mission against the Islamic State group in Iraq was estimated at more than $100 million, according to officials Tuesday.

The independent parliamentary budget office put the tally at Can$128.8 million (US$103.8 million) to Can$166.40 million (US$134.1 million).

Canadian police have charged two people in an alleged Valentine's Day plot to carry out a mass shooting at a Halifax mall then commit suicide, authorities said Saturday.

Lindsay Souvannarath, a 23-year-old woman from the U.S. city of Geneva, Illinois was charged with conspiracy to commit murder along with Randall Shepherd, 20, from Halifax in Nova Scotia, Royal Canadian Mounted Police Assistant Commissioner Brian Brennan told a news conference.

Al-Jazeera journalist Mohamed Fahmy said Saturday he has urged Canada to push for his speedy deportation from Egypt after he spent more than 400 days in a tiny prison cell.

On Thursday, a court ordered that Fahmy and his colleague, Egyptian producer Baher Mohamed, be freed pending their retrial.

Canada welcomed Thursday Egypt's release on bail of Al-Jazeera journalist Mohamed Fahmy, but decried as "unacceptable" putting him through a retrial.

"While we welcome Mohamed Fahmy's release on bail, we continue to call for his immediate and full release," Canadian Consular Affairs Minister Lynne Yelich said.

Canada vowed Wednesday to keep open an observatory in eastern North America where the first dark skies reserve was created, hours after its director said budget cuts would force its closure.

"Our government will pay to keep the Observatoire Astronomique du Mont-Mégantic open for the two years," International Development Minister Christian Paradis said in a Twitter message.