MOGADISHU, Somalia (AP):

The most powerful bomb blast ever witnessed in Somalia's capital killed at least 231 people with more than 275 injured, a senator said Sunday, making it the deadliest single attack in this Horn of Africa nation. The toll could continue to rise.

Abshir Abdi Ahmed cited doctors at overwhelmed hospitals he visited in Mogadishu a day after a truck bomb targeted a crowded street near key government ministries. Many of the bodies in mortuaries had not yet been identified, he said.

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.

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 US Embassy bombings in Kenya and Tanzania in 1998.

HORRENDOUS EVENT

Doctors at Mogadishu hospitals struggled to assist badly wounded victims, many burned beyond recognition. "This is really horrendous, unlike any other time in the past," said Dr Mohamed Yusuf, the director of Medina hospital.

Inside, bleary-eyed nurses transported a man whose legs had been blown off. He waited as surgeons attended to another badly injured patient. Exhausted doctors struggled to keep their eyes open, while screams from victims and newly bereaved families echoed through the halls.

"Nearly all of the wounded victims have serious wounds," said nurse Samir Abdi. "Unspeakable horrors." The smell of blood was strong.

A teary-eyed Hawo Yusuf looked at her husband's badly burned body. "He may die waiting," she said. "We need help."

Ambulance sirens echoed across the city as bewildered families wandered in the rubble of buildings, looking for missing relatives. "In our 10-year experience as the first responder in #Mogadishu, we haven't seen anything like this," the Aamin Ambulance service tweeted.

Grief overwhelmed many.

"There's nothing I can say. We have lost everything," wept Zainab Sharif, a mother of four who lost her husband. She sat outside a hospital where he was pronounced dead after hours of efforts by doctors to save him.

The country's Somali-American leader, President Mohamed Abdullahi Mohamed, declared three days of mourning and joined thousands of people who responded to a desperate plea by hospitals to donate blood. "I am appealing to all Somali people to come forward and donate," he said.