Somalia is appealing for blood to treat those wounded in Saturday’s huge truck bombing in the capital, Mogadishu, which killed at least 281 people.
Information Minister Abdirahman Osman told the BBC the death toll was likely to rise, and more help was needed.
He said more than 300 people had been injured in Somalia’s deadliest terror attack in 10 years, and more bodies were trapped under rubble.
Two planes of medial aid – from the US and Qatar – have landed in the capital.
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Mr Osman blamed the Islamist al-Shabab group, which is allied to al-Qaeda, for the attack.
The minister thanked the hundreds of Mogadishu residents who had already donated blood.
Somalia does not have a blood bank, which was hampering some of the aid efforts, he told the Reuters news agency.
Ahmed Adan, from the BBC Somali Service, says a youth group, with the help of the government, has started a social media campaign to raise money for the families of the victims and organise blood donations for the injured.
In Kenya, hundreds of people have been queuing to give blood in the Nairobi suburb of Eastleigh, known as “Little Mogadishu”.
On Monday, 165 unidentified bodies were buried by the authorities.
There were burnt beyond recognition and there was no means of identifying them.
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Of those who were identified, one of the victims was a medical student due to graduate the next day.
Maryam Abdullahi’s father had flown to Mogadishu to attend her graduation but instead witnessed her burial.
The truck exploded at a busy junction, destroying hotels, government offices and restaurants.
A 22,000-strong African Union force is in the country trying to help the government recapture territory from al-Shabab, whose fighters are active in much of rural southern Somalia.
Mr Osman said the UN-backed government had been calling for an easing of an arms embargo on Somalia for years.
“Our security forces are not enabled to carry out sophisticated security operations that will stop such attacks,” he told the BBC’s Newsday programme.