The suspect has been identified as Albert John Olanda, who entered Kenya from Tanzania on October 23. At the time of the blast, he was found carrying only a passport and a notebook with several mobile phone numbers.

A second suspect has been taken into custody by police after being arrested in Nairobi's Kibera slum. Kiraithe said he was being interrogated for any further information on the blast.

This is the second attack that has occurred in Nairobi in the month of December. Three Kenyan police officers were killed in two separate grenade attacks on December 3 in Nairobi's Eastleigh neighborhood. While no connection has yet been established between the two, Kiraithe revealed the Russian made grenade that exploded last night was similar to those used in early December.

The Kenyan government reportedly has reached out to the U.S. Federal Bureau of Investigation for help in probing the attacks.

Olanda was en route to the Ugandan capital, which officials believe was the intended site of the attack. Kampala also was the site of twin suicide blasts in July, which killed 74. Responsibility for the attack was claimed by Somali insurgent group al Shabab. Shabab, which has ties to al-Qaida, claimed the act was retaliation for Ugandan peacekeeping troops in Mogadishu.

It is not yet known whether the Nairobi explosions are the work of al Shabab, but Kiraithe said the security services are concerned with the increasing amount of Somalis and Ethiopians illegally entering the country.