(Bloomberg) -- Boko Haram Islamist militants operating in Africa’s Lake Chad region killed 92 Chadian soldiers and 47 Nigerian troops in separate attacks on the same day, dealing a blow to a multinational effort to defeat their 11-year-old insurgency.

At least 92 soldiers were killed and 47 injured in the attack on troops on Monday in the southern village of Boma on the shores of the lake near Chad’s common frontiers with Nigeria and Niger.

“I have taken part in many military operations and led many operations as well but never in our history have we lost so many men in one single attack,” Chadian President Idriss Deby said in a You-tube video of his visit to the attack site.

In Nigeria, at least 47 Nigerian soldiers were killed in an ambush in the northeastern town of Gorgi in a convoy of troops sent to reinforce the front lines, according to John Enenche, a military spokesman.

Nigeria, Chad, Niger and Cameroon are members of a multinational force formed to defeat Boko Haram, which had embarked on a jihad in Nigeria in 2009 before spreading to neighboring countries.

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