Police in Nairobi say they have arrested more than 300 people in an overnight swoop in Eastleigh estate, the scene of Monday night’s blast.
At least six people were killed and several were injured in explosions in the area.
This is the latest in a series of terror attacks in Kenya since the Kenya Defence Forces entered Somalia.
Police carried out an overnight raid in the Eastleigh neighbourhood and arrested more than 300 people.
It is not clear if they were involved in the attack – but the Kenyan government has ordered all refugees back to the camps and it is likely some of those arrested may have been those without proper documentation.
Eastleigh is dominated by refugees from Somalia, seeking shelter from years of conflict in their country. In December last year, a similar blast in the area killed four people, and less than a week ago one person died as an improvised explosive device he was assembling accidentally went off.
Kenya’s President Uhuru Kenyatta has warned that his government will deal ruthlessly with terrorists, but many Kenyans feel the president is paying lip service to security matters in the country.