NAIROBI, Jan. 16 (Xinhua) -- Kenyan police said Wednesday they are holding two key suspects in connection with the attack on a luxury hotel and office complex in Nairobi that left 14 civilians killed and several others injured.

George Kinoti, director of Directorate of Criminal Investigation under the National Police Service, said the two were arrested in Eastleigh and Ruaka residential estates in Nairobi, hours after security forces ended 18-hour siege at the dusitD2 complex on 14 Riverside Drive.

Kinoti who was involved in the security operation at the hotel said one of the attackers lived in Ruaka.

"The suspects are providing good information on the incident. They had contacts with the slain men," he said, noting that they were looking for more suspects into the incident.

The arrest came a few hours after President Uhuru Kenyatta declared the terrorist attack at the 14 Riverside Drive over, saying security officers killed all the terrorists.

Kenyatta did not mention the number of the attackers who had stormed the business complex that houses hotels and multinational companies.

The president who had earlier convened a national security council meeting said the government will dedicate efforts to rooting out terrorism that has remained a grave national security threat.

"Throughout the breadth of Kenya and in our immediate neighborhood, multiple security efforts are underway to detect, deter, disrupt and defeat terrorist operatives or groups," said Kenyatta.

Somali terrorist group al-Shabab claimed responsibility for the Tuesday attack.