Twelve soldiers were wounded in the attacks staged by the terrorists on Thursday and Friday near the border town of Fotokol, according to a military statement read out on national television.
Chad sent a convoy of troops and military vehicles into neighboring Cameroon on January 17 to deal with the growing threat Boko Haram poses in the region.
"The enemy was repelled by our defensive forces," the general staff's statement said, adding that the troops had "routed" the Takfirirs in the second attack.
The soldiers were killed by improvised explosive devices, the statement said.
A senior Cameroonian security source said the Chadian troops were deployed to the town, which sits opposite a Nigerian town under Boko Haram control and is also close to the border with Chad, on Wednesday.
Boko Haram terrorist group frequently stages attacks on Fotokol from their base in the Nigerian town of Gamboru, which is just 500 meters (yards) away.
Chad has called on countries in the region to form a broad coalition in the fight against the terrorist group. The country has already deployed its army along its borders as well as sending the additional contingent to Cameroon.
Chad's president Idriss Deby has also expressed intentions of taking back the strategic Nigerian town of Baga from Boko Haram, situated on Lake Chad.
More than 13,000 people have been killed and more than one million made homeless by Boko Haram violence since 2009.
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