Elgiva Bwire Oliacha, 28, pleaded guilty in court on Wednesday to nine charges, including being responsible for Monday’s twin grenade blasts.
The blasts came about a week after hundreds of Kenyan forces moved into neighboring Somalia to attack Al-Shabab militants.
Al-Shabab, Somalia’s most dangerous militant group, threatened to carry out terror attacks in Kenya in retaliation. Police arrested the suspect on Tuesday and said that he was from a Kenyan tribe and was not ethnic Somali.
Meanwhile, a Somali man who was believed to have been kidnapped with two other aid workers in northern Somalia is in police custody, the trio's Danish employer said Wednesday.
The Danish Refugee Council says the aid worker has been held since Tuesday. It said Wednesday "his role in the incident will be further investigated," but declined to give further details. The council said the other two members of the group's de-mining unit, an American and a Dane, remain unaccounted for after Tuesday's kidnapping by gunmen.
"We have good contacts in the country. For the moment, we are working closely with the local authorities and we are all aiming to resolve the situation as soon as possible," said Ann Mary Olsen, head of the Danish Refugee Council's international department.
"Somalia and the rest of the Horn of Africa is in the midst of a humanitarian crisis. People are in acute need of relief aid and it is quite tragic that we are targeted like this," Olsen added.
The three were working in northern Somalia for the Danish Demining Group, whose experts have been clearing mines and unexploded ordnance in conflict zones in Africa and the Middle East.
The American woman is 32 years old, while the Dane is 60. No names were released.
Following the abductions in the Somali town of Galkayo, which is partly under clan control, activities of the Danish Demining Group have been suspended in the area.
A self-proclaimed Somali pirate has said pirates had captured the three and would not harm them, but will want a ransom for their release. The claim could not be independently verified.
The kidnapping comes only weeks after the seizure of two women working for Doctors Without Borders from a refugee camp in neighboring Kenya, as well as the kidnappings of two European tourists from Kenya's coast — one of whom later died. Somali gunmen were suspected in those attacks.
