Explosions in the port town of Bosasso, the commercial capital of the self-declared autonomous region of Puntland, northeastern Somalia, killed 21 people and injured 69 others on 5 February, a senior official said.
"At around 8pm last night, two consecutive explosions killed 21 Ethiopian migrants and injured 69 others near the port area," Abdirizaq Hareed, the mayor of Bosasso, told IRIN on 6 February.
Puntland has been relatively peaceful compared with the rest of the country.
"This is the first incident of its kind," said Hareed. "It was an inhuman act. I cannot imagine why someone would target these people," he added.
A local journalist told IRIN said there was an "air of disbelief" in Bosasso. "It is all people are talking about and wondering what next. We are not used to this kind of thing."
Authorities have not yet established who was responsible for the blast. "The police are following a number of leads in their investigation but we will not rest until we capture the culprits," said Hareed.
Hareed assured the residents that the authorities were in control of the situation and would "do everything possible to safeguard peace".
Yassin Farah Artan, a doctor, told IRIN that 69 people were in hospital and that some of them had "horrific injures".
He said hospital wards were full and some casualties were being treated in the corridors, adding that the death toll could rise given the severity of some injuries.
Almost all the injured were Ethiopian migrants.
Bosasso has become a magnet for thousands of would-be migrants from southern Somalia and Ethiopia, willing to risk all for a dangerous voyage across the Gulf of Aden to Yemen hoping to find a better life.
The journey is treacherous and hundreds of people die at sea every year when often overloaded boats capsize or sink in the shark-infested waters or are forced to jump into the sea by the smugglers.
Bosasso, the main port of Puntland, has been relatively peaceful compared with southern Somalia where the transitional government backed by Ethiopian forces has been fighting insurgents since the Islamist courts were ousted from Mogadishu by Ethiopians troops in December 2006.