At least 14 people were killed and 74 injured were Saturday in a suicide bomb attack at a crowded market in Chad's capital, N'Djamena.
The incident came hours after at least 10 villagers were slain in Ngamdu, Nigeria, when Boko Haram Islamic extremists attacked their settlement and took over a major highway in the region.
Boko Haram claimed responsibility for the Chad attack, as well for a second Nigerian attack, this one in the city of Maiduguri, the SITE Intelligence Group said.
The U.S.-based monitoring group said the claim, made on Twitter, was signed "Islamic State, West Africa Province," as Boko Haram has styled itself since pledging allegiance to the Islamic State group in March.
"Our current count is 15 dead," N'Djamena police spokesman Paul Manga said. The total included the suicide bomber — a man dressed in a woman's burqa.
Chad authorities banned the head-to-toe religious garment last month, citing the risk that attackers could use it as a disguise or hide explosives
The bomber attempted to enter the market, then detonated his bomb when military police tried to stop him, Manga said.
In the Ngamdu attack, a local police official who spoke on condition he not be named said the victims were all shot when the extremists stormed their village and fired at fleeing residents. Many other residents were wounded, the official said.
In Maiduguri, two people were killed when two suicide bombers tried to target a busy bus station. Heavy security prevented the attackers from getting into the terminal.
Maiduguri is Boko Haram's birthplace.
The attacks underlined the threat still posed by the Islamist militants, despite claimed military successes in recent months and with a new regional force set to take on the group at the end of the month.
Some information for this report came from AFP.