N'DJAMENA, Chad (AP) -- Suicide bombers on motorcycles simultaneously attacked two buildings including the national police academy in Chad's capital on Monday, killing at least 10 people in the first attack of its kind since Islamic militants threatened the country earlier this year, witnesses said.
There was no immediate claim of responsibility for the attack on N'Djamena but suspicion fell on Boko Haram, the jihadist group based in neighboring Nigeria that already has attacked Chadian villages along the lake that divides the two countries.
Chad has been a major military ally in the fight against the insurgent group, and Boko Haram's leader has publicly threatened the Chadian president in retaliation.
Witnesses said a suicide bomber on a motorcycle blew himself up outside a government building where the head of the national police is based after security officers unsuccessfully tried to subdue the attacker by shooting at him.
A police official who spoke on condition of anonymity as he was not authorized to speak to the media said at least 10 people had been killed in that attack.
A second explosion also went off at the headquarters of the national police academy in the capital at the same time, witnesses said.
Boko Haram's leader back in February had taunted the Chadian president.
"You sent 7,000 of your soldiers. Why didn't you send 7 million? This is few... 7,000? By Allah, it is small. We can capture them in an attempt or two," he said, according to a transcript later released by SITE Intelligence Group.