Suspected Boko Haram fighters blew themselves up during a police raid in Chad's capital early on Monday, killing five officers and six militants, police and government officials said.
The raid of an illegal arms cache was part of a security operation aimed at dismantling a network of Boko Haram militants blamed for twin suicide bombings in N'Djamena on June 15.
The apparently synchronized attacks were the most deadly that Western ally Chad has known and killed 34 people.