Updated 6:20 a.m. ET Monday

In the Somali capital of Mogadishu, funerals have begun for those killed in Saturday's truck bombing. Officials have cautioned that the death would continue to rise from the nation's worst-ever attack.

The government's latest figures show more than 300 people were killed and another 300 others wounded in the explosion. The Associated Press reports that overwhelmed hospitals in Mogadishu are struggling to assist other badly wounded victims, many burned beyond recognition.

NPR's Eyder Peralta reports rescue workers are trying to get dogs onto the scene to sniff out bodies still trapped under mountains of flattened buildings.

The massive explosion was set off Saturday on a busy street close to the foreign ministry in Mogadishu and detonated outside of the Safari Hotel. Several building were destroyed in the blast, reducing them to burning piles of rubble and twisted metal.

A second improvised explosive device erupted in the Medina district two hours later, Eyder said.

The truck bomb was detonated in the busiest intersection in Mogadishu.

Residents and emergency responders described horrific scenes of devastation including charred, unrecognizable bodies amid the debris.

"In our 10 year experience as the first responder in #Mogadishu, we haven't seen anything like this," Aamin Ambulance workers tweeted.

Families and rescue workers continue to search through the wreckage into Sunday. Hours after the blast many took to social media to report burned bodies that remained on the road.

In an address to the nation, President Mohamed Farmaajo declared three days of mourning "for innocent victims." He also called on residents to donate blood and pray.

"Today's horrific attack proves our enemy will stop at nothing," Farmaajo said, adding a plea to come together. "Let's unite against terror," he urged.

"Terror won't win," he exclaimed in a separate tweet.

No one has taken responsibility for the attack. But Yarisow told NPR he blames the al-Qaida-linked al-Shabab extremist group for the attack. He believes this is the "terrorists" striking back against the government because of its renewed offensive against Al-shabab.

"Since we have put more pressure on them, since we are winning the war, they are trying to cause as many civilian casualties as possible," Yarsiow said.

"Even for a city as battered as Mogadishu," he added, "this is truly tough."

The Islamist group has often targeted Mogadishu and the president has made fighting the group one of his top priorities.

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