Latest: Somalia truck bomb death toll rises to 231

Many of the bodies in mortuaries had not yet been identified, he said.

Officials feared the toll would continue to climb from Saturday's lorry bomb that targeted a busy street near key ministries.

Doctors struggled to assist horrifically wounded victims, many burned beyond recognition.

"The hospital is overwhelmed by both dead and wounded," said Dr Mohamed Yusuf, the director of Medina hospital.

"This is really horrendous, unlike any other time in the past."

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.

social=twitter]https://twitter.com/RT_com/status/919481245884706816[/social]

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 all Somali people to come forward and donate," he said.

Angry protesters gathered near the scene of the attack as Somalia's government blamed the al Qaida-linked al Shabab extremist group for what it called a "national disaster".

However, al-Shabab, which often targets high-profile areas of the capital with bombings, had yet to comment.

"They don't care about the lives of Somali people, mothers, fathers and children," prime minister Hassan Ali Khaire said.

"They have targeted the most populated area in Mogadishu, killing only civilians."

Rescue workers searched for survivors trapped under the rubble of the largely destroyed Safari Hotel, which is close to Somalia's foreign ministry.

The explosion blew off metal gates and blast walls erected outside the hotel.

The United States condemned the bombing, saying "such cowardly attacks reinvigorate the commitment of the United States to assist our Somali and African Union partners to combat the scourge of terrorism".

But the US Africa Command said US forces had not been asked to provide aid.

A spokesman said emergency personnel and local enforcement would handle the response and "the US would offer assistance if and when a request was made".

The US military has stepped up drone strikes and other efforts this year against al Shabab, which is also fighting the Somali military and over 20,000 African Union forces in the country.

The United Nations special envoy to Somalia called the attack "revolting," saying an unprecedented number of civilians had been killed.

Michael Keating said the UN and African Union were supporting the Somali government's response with "logistical support, medical supplies and expertise".

Saturday's blast occurred two days after the head of the US Africa Command was in Mogadishu to meet with Somalia's president, and two days after the country's defence minister and army chief resigned for undisclosed reasons.

Update 1.30pm: The death toll from the most powerful bomb blast witnessed in Somalia's capital rose to 189 with more than 200 injured, making it the deadliest single attack ever in the Horn of Africa nation, police and hospital sources said.

Doctors struggled to assist horrifically wounded victims, many burnt beyond recognition. Officials feared the toll would continue to climb from Saturday's truck bomb that targeted a busy street near key ministries.

Ambulance sirens still 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.

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 for the wounded victims.

"I am appealing all Somali people to come forward and donate," he said.

"The hospital is overwhelmed by both dead and wounded. We also received people whose limbs were cut away by the bomb. This is really horrendous, unlike any other time in the past," said Dr Mohamed Yusuf, the director of Medina hospital.

Overnight, rescue workers with torch lights searched for survivors trapped under the rubble of the largely destroyed Safari Hotel, which is close to Somalia's foreign ministry. The explosion blew off metal gates and blast walls erected outside the hotel.

Somalia's government has blamed the al Qaida-linked al-Shabab extremist group for the attack it called a "national disaster". However, al-Shabab, which often targets high-profile areas of the capital with bombings, had yet to comment.

"They don't care about the lives of Somali people, mothers, fathers and children," Prime Minister Hassan Ali Khaire said. "They have targeted the most populated area in Mogadishu, killing only civilians."

Somalia's information minister, Abdirahman Omar, said the blast was the largest the city had ever seen.

"It's a sad day. This how merciless and brutal they are, and we have to unite against them," he said, speaking to the state-run radio station.

The United States joined the condemnation, saying "such cowardly attacks reinvigorate the commitment of the United States to assist our Somali and African Union partners to combat the scourge of terrorism."

The US military has stepped up drone strikes and other efforts this year against al-Shabab, which is also fighting the Somali military and over 20,000 African Union forces in the country.

Saturday's blast occurred two days after the head of the US Africa Command was in Mogadishu to meet with Somalia's president, and two days after the country's defence minister and army chief resigned for undisclosed reasons.

Earlier: The death toll from a truck bomb blast in Somalia’s capital has risen to 53, security and medical sources said.

More than 60 others were injured.

Police Captain Mohamed Hussein said many victims died at hospitals from their wounds.

Somalia’s government has yet to release the exact death toll from an explosion many called the most powerful they had ever witnessed in Mogadishu.

President Mohamed Abdullahi Mohamed has joined thousands of people who responded to a desperate plea by hospitals to donate blood for the wounded victims.

The explosion appeared to target a hotel in a busy road in Hodan district. Police said security forces had been trailing the truck after it raised suspicions.

The blast occurred two days after the head of the US Africa Command was in Mogadishu to meet Somalia’s president and two days after the country’s defence minister and army chief resigned.

Somalia-based extremist group al-Shabab recently stepped up attacks on army bases across south and central Somalia.

While there was no immediate claim of responsibility for Saturday’s blast, al-Shabab often targets high-profile areas of Mogadishu with deadly bombings.

The US military has stepped up drone strikes and other efforts this year against the al Qaida-linked al-Shabab, which is also fighting the Somali military and more than 20,000 African Union forces in the country.

AP