There is currently a United Nations arms embargo on Somalia
The African Union has called on the international community to send weapons to the UN-backed Somali government to help it fight Islamist militants.
The AU envoy to Somalia made the plea in the wake of the suicide attacks in Mogadishu in which 17 AU peacekeepers were blown up by the al-Shabab group.
"If we go after Shabab, we'd destroy them in no time," said Nicolas Bwakira.
He said the attacks should not deter countries from keeping to their promises to bolster the AU force.
The force currently operates with 5,000 soldiers, instead of an intended 8,000. Nigeria and Ghana have promised troops, but so far these pledges remain unfulfilled.
The UN has also said it will take over the mission - at an unspecified date.
Mr Bwakira told journalists in the Kenyan capital, Nairobi, that the deadly attack has not demoralised the force, despite more threats from al-Shabab.
"Peacekeepers do not come to play football or go to the beach - there is a risk to peacekeeping."
But he said the transitional government needed help to fight its "enemies".
"To be fighting with enemies, they need arms - arms which are superior to the capacity of Shabab's."
The BBC's Anne Waithera in Nairobi says there is currently an arms embargo on Somalia, but the United States has been supplying arms to the government after seeking an exemption from the UN.
Our reporter says those injured in Thursday's blasts are still being airlifted to neighbouring Kenya for treatment.
Nine peacekeepers were flown to Nairobi on the day of the attack and an additional 20 arrived on Friday morning.
The deputy commander of the AU force in Somalia died in the attack when two vehicles with UN logos, packed with explosives, were driven into a peacekeeping base by the airport.
Shelling after the double bombing on Thursday left at least 13 people dead, mostly civilians, witnesses say.
"We do not run away when the situation worsens," said Lt Col Felix Kulayigye, a spokesman for the Ugandan military, which contributes about half of the 5,000-strong AU force.
Burundi, the only other country to have sent peacekeepers to Somalia, has declared five days of national mourning for the 12 of its peacekeepers who died.
But a Burundian government spokesman said it would not pull out.
The Islamist al-Shabab group said the attacks were revenge for a US raid on Monday.
This reportedly killed Kenyan-born al-Qaeda suspect Saleh Ali Saleh Nabhan, who was wanted by the US for attacks in Kenya.
UN Secretary General Ban Ki-moon condemned the blast in the "strongest terms".
It is believed Nabhan fled to Somalia after the attacks and was working with al-Shabab, which the US sees as al-Qaeda's proxy in Somalia.
Al-Shabab and its allies control most of southern and central Somalia, while the government, helped by the AU force, just runs parts of Mogadishu.
The country has not had a functioning central government since 1991, leading to a complete breakdown of law and order both on land and in recent years in Somali waters.
President Sheikh Sharif Sheikh Ahmed, a moderate Islamist and former insurgent, was chosen in January after UN-brokered peace talks.
He has vowed to implement Sharia but al-Shabab accuses him of being a Western puppet.
Years of fighting and anarchy have left some three million people - half the population - needing food aid.