Kenya: Second explosion in Nairobi
A blast has gone off at a bus stop in Kenya's capital, Nairobi, killing at least one person, police say.
An earlier grenade attack on a bar in the city wounded 12 people.
The attacks happened two days after the US embassy in Kenya warned that an attack by Islamist militants from neighbouring Somalia was imminent.
But Kenyan Police Commissioner Matthew Iteere said there was no evidence linking the nightclub attack to the militants from the al-Shabab group.
The Kenyan government sent troops to Somalia more than a week ago to pursue the militants after accusing them of being behind a spate of abductions on its territory.
Al-Shabab, which is linked to al-Qaeda and controls much of southern and central Somalia, denies involvement in the kidnappings but has warned of reprisals if Kenyan troops do not withdraw from Somalia.
Police said the explosion on Monday evening occurred at the OTC bus terminal in downtown Nairobi, which is usually a busy part of the city.
Kenya's Red Cross said on its Twitter feed that eight casualties had been rushed to Kenyatta National Hospital.
The BBC's Odhiambho Joseph in Nairobi says 18 people were wounded in total.
Eyewitnesses told the BBC that the blast happened after a hand grenade was thrown at a moving matatu minibus taxis which bounced back and exploded where passengers were waiting for transport.
In the early hours of Monday morning a man threw a grenade into the Mwauras nightclub and fled the scene, witnesses said. No-one has claimed responsibility for the attack.
Our reporter says the attacks have prompted the authorities to ban fireworks for this week's Hindu festival of Diwali.
Last December three people died during a grenade attack at a bus in Nairobi. It was never clear who was behind it.
Correspondents say that although both attacks were small, they will nevertheless cause a great deal of anxiety in Kenya.