The most powerful bomb blast ever witnessed in Mogadishu, Somalia’s capital killed 276 people with around 300 others injured, the country’s information minister,  Information Minister Abdirahman O. Osman said early Monday morning, making it the deadliest single attack in this Horn of Africa nation.

The attack occurred when a truck carrying explosives detonated Saturday in a crowded street packed with cars and pedestrians, near government ministries and hotels.

In a tweet, Abdirahman Osman called the attack “barbaric” and said countries including Turkey and Kenya had already offered to send medical aid. Hospitals were overwhelmed a day after a truck bomb targeted a crowded street near key government ministries, including foreign affairs.

As angry protesters gathered near the scene of the attack, Somalia’s government blamed the al-Qaida-linked al-Shabab extremist group for what it called a “national disaster.” However, Africa’s deadliest Islamic extremist group, which often targets high-profile areas of the capital, had yet to comment.

Al-Shabab earlier this year vowed to step up attacks after both the Trump administration and Somalia’s recently elected president announced new military efforts against the group.

Somali President Mohamed Abdullahi Farmaajo said the attack showed Somalia’s enemies cared nothing for human lives.

“Today’s horrific attack proves our enemy would stop at nothing to cause our people pain and suffering. Let’s unite against terror,” he tweeted. The president declared three days of mourning and called on citizens to donate blood as hospitals struggled to save critically injured civilians.

After the president visited Medina Hospital on Sunday morning to give blood and comfort victims, hundreds more Somalis flocked to hospitals to donate blood.

Relatives of missing people arrived at hospitals Sunday desperate for news of loved ones. Others wandered around the ruins of buildings hit the blast.

Many of the dead had not been identified, with dozens burned beyond recognition.

The Mogadishu bombing is one of the deadliest attacks in sub-Saharan Africa, larger than the Garissa University attack in Kenya in 2015 and the U.S. Embassy bombings in Kenya and Tanzania in 1998.