A blast has gone off at a bus stop in Kenya's capital, Nairobi, killing¹ at least one person, police say.

肯尼亚警方称，首都内罗毕一座公交车站发生爆炸案，至少一人死亡。

Witnesses said a man threw a grenade into the nightclub and fled the scene overnight
An earlier grenade（手榴弹） 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 militants² from neighbouring Somalia was imminent³（即将来临的） .

But Kenyan Police Commissioner⁴ 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 spate⁵ of abductions（绑架） 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 reprisals⁶（报复） 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.

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.

The BBC's Will Ross in Nairobi says last December three people died during a grenade attack at a bus in Nairobi. It was never clear who was behind it.

Our correspondent adds that although both attacks were small, they will nevertheless cause a great deal of anxiety in Kenya.