The attacks happened in the villages of Mabass and Makxy in the Mayo-Tsanaga Division of the Far North Region of Cameroon on Sunday morning, Saiid Abdulkarim, a journalist for the state broadcaster, told CNN.

Three of those kidnapped were found dead, Abdulkarim said.

The Cameroonian government did not immediately comment.

Meanwhile, thousands of Chadian troops arrived in Cameroon to join that country's soldiers in the fight against Boko Haram.

The governor of Cameroon's Far North Region, Mijiyawa Bakary, told CNN that the first contingent of Chadian troops arrived in a convoy of more than 400 vehicles, and a second wave of soldiers were expected to arrive soon.

The Chadian soldiers "are coming in with dozens of tanks, armored vehicles and other military equipment," Cameroon defense ministry spokesman Col. Didier Badjeck said.

The Chadian parliament unanimously voted Friday to send troops to Cameroon and Nigeria to join in the fight against Boko Haram.

The move comes after Cameroon's President, Paul Biya, made a strong call for international cooperation in the fight against Boko Haram.

Biya told diplomats recently that Boko Haram was "a global threat" that calls "for a global response."

"Such should be the response of the international community, including the African Union and our regional organizations," he said.

Chadian officials concluded that Boko Haram also poses a danger to Chad.

Chadian President Idriss Deby said attacks on Cameroon by the terrorist group could destroy Chad's economy.

"We can't remain indifferent to what is happening to our neighbors," Deby said. "Cameroon is the entry and exit point for Chad economically."

Much of what is imported to Chad comes through the Cameroonian seaport of Douala, and Chad's crude oil is transported through a pipeline that runs from southern Chad to a floating facility 11 kilometers (almost 7 miles) off the Cameroon coast.

The presence of Chadian troops on the front could be key to reversing the gains so far made by the terrorist group.

Trained in desert combat, Chadian forces played a critical role in fighting jihadists in northern Mali, where they became major allies to French troops in the fight against terrorists there. In fact, they were instrumental in the killing of some high-profile jihadists.

The involvement of Chadian troops marks a major shift in Cameroon-Chad anti-terrorism cooperation. In the past year, it focused mostly on securing individual borders.

While Chad is the first country to put boots on the ground in Cameroon, the international community and regional bodies are also expressing concern.

On Friday, the Russian ambassador to Cameroon, Nicolay Ratsiborinski, said his country will supply Cameroon with modern and sophisticated military weapons.

He said the equipment will include heavy artillery, armored cars and missiles.

Michael Stephen Hoza, U.S. ambassador to Cameroon, also said his country would help train Cameroon soldiers and offer equipment for the fight.

Boko Haram has been staging cross-border raids on Cameroon, the latest being the attempt by the insurgents to take over a Cameroon military base in Kolofata. Cameroonian troops killed 143 of them, and lost one soldier.

On January 3, Boko Haram fighters briefly took over control of a military base in Achigashia, forcing Cameroonian soldiers to retreat and then for the first time use airstrikes against the insurgents.

Attacks on military installations mark a big shift in Boko Haram operations in Cameroon. Initially,they would cross the border and either attack to steal food or kidnap nationals and expatriates in exchange for ransoms.

Cameroon has already deployed about 7,000 troops across the Far North, where Boko Haram has scaled up attacks over the past six months.

(CNN)