3 dead in Kenya bus station blast March 10, 2012 -- Updated 2000 GMT (0400 HKT) NEW: Police believe it was a grenade attack NEW: They suspect Al-Shabaab or sympathizers of Al-Shabaab may be responsible Nairobi, Kenya (CNN) -- At least three people were killed and others were treated for wounds following explosions at a bus station in the Kenyan capital Saturday, the Red Cross said. The explosions occurred in central Nairobi, the agency said. "Scores" of people were rushed to the Kenyatta National Hospital for treatment, the Red Cross said. At least 40 people were injured, including eight critically. The explosions happened at the Machakos Country Bus station, which sends buses to the city of the same name southeast of Nairobi. "We still need to complete investigations and we can not immediately confirm who did this, but we highly suspect that it is Al-Shabaab or sympathizers of Al-Shabaab," police deputy spokesman Charles Owino told CNN. Police believe that it was a grenade attack. "Eyewitnesses say that grenades were thrown from a vehicle and the suspected perpetrators fled from the scene," he said.