However, Kenya authorities have placed the blame squarely on the shoulders of al-Shabaab, the Somali group that is linked to al-Qaeda and has been responsible for similar attacks in the past.
The group of militants was the one that were responsible for the Westgate Mall attack last September in Nairobi, which killed 67 people. Since the mall blast, there have been a number of other incidents.
Nelson Marwa a county commissioner in Mombasa said someone threw a grenade at the passengers. Marwa said the attackers had been on a motorcycle and threw the grenade at people waiting for the bus.
Over 20 people were wounded in that attack.
Guards at the Reef Hotel along the shoreline said they prevented attackers from entering the hotel, but the same suspects threw a bag containing an explosive device in the area of the hotel.
One roof was torn off from the bomb blast, while a wall partially collapsed.
People who had been at the station waiting for the bus were sprawled out in pools of blood with the road full of shattered glass from the buses.
The large Muslim population along the Kenyan coast feels marginalized by the Kenyan government. The area is a big recruitment location for Islamist militant networks.
Uhuru Kenyatta the President of Kenya has described the tourism industry as being on its knees because of the attacks by the Islamist militants that do not want Kenyan troops in Somalia. Those demands have been rejected by Kenyatta.
Mombasa draws large numbers of tourists due to its location on the African coast and its deep history. The city is also a large port that is major in the region. The city is on the Indian Ocean.