Officials in Chad have launched a sweeping security clampdown in the capital, N’Djamena, in the wake of purported Boko Haram attacks in the city.

Army troops and police officers were seen patrolling the streets on Tuesday, a day after twin bombings killed 24 people and injured dozens more.

Security was high around the presidential palace, while the compound of police headquarters, a target of the Monday attacks, was sealed off by security forces.

Police barred cars with tinted windshields from the streets while vehicles travelling near busy places, including mosques, churches and markets were routinely searched.

No group has yet claimed responsibility for the Monday attacks, which were the first of such magnitude in the capital. However, officials have blamed the bombings on Boko Haram, a Takfiri group known for its extensive terror campaign in Nigeria and some neighboring countries.

Chad has been one of the active members of a regional alliance fighting the terrorist group with security forces on high alert in border areas fearing Boko Haram’s reprisal offensives.

Health officials in Chad also warned Tuesday that many of the wounded in the attacks are at risk of dying due to shortage of blood.

“Many of the injured risk dying if the public does not come forward to donate blood,” nurse Ache Zenaba warned.

The government of President Idriss Deby tried to ensure people of safety and security in the capital city. An official statement said that the situation is “entirely under control,” adding, “These attacks, which aimed to strike fear into the people, will not slacken Chad’s determination to combat terrorism.”

About 15,000 people have been killed and around 1.5 million others displaced since Boko Haram started its militancy in 2009. It says its main goal is to overthrow the Nigerian government.