N'Djamena (Chad), June 17 (IANS): The toll in Monday's twin suicide attacks in Chad's capital N'Djamena has risen to 37, including the four suicide bombers, the country's President Idriss Deby Itno said in a televised broadcast.

Deby Itno on Tuesday night strongly condemned "this horrible and barbaric act committed by terrorists", and promised that the crime would not go unpunished, Xinhua news agency reported on Wednesday

He urged his fellow citizens to remain calm, to double their vigilance and effectively cooperate with the security services to neutralise any attempt to destabilise the country.

"Chad will never bow to blackmail by terrorists," the president declared.

On Monday morning, suicide bombers targeted the National Police School and the central police station which is situated a few metres from the presidential palace of the central African republic.

The provisional toll that had been published on Monday by the government was 27, including the four terrorists and about 101 others were injured.

The Chadian government, which has deployed troops to participate in operations against the Islamist Boko Haram in Cameroon, Nigeria and Niger, has blamed this terrorist group for the twin attacks, the first of its kind in N'Djamena.