By Andrew Cawthorne and Jeremy Clarke
NAIROBI (Reuters) - An apparent bomb blast in a Nairobi street on Monday killed one person, injured dozens and left a severed leg hanging from a shattered window.
A senior policeman at the scene said the explosion, which also left a mangled corpse in the street and sent passers-by flying through the air, seemed to be a suicide bombing.
"This sort of attack is very unusual for Nairobi," he said.
Witnesses saw a man with a package running down the road just moments before the blast at around 8 a.m. (0500 GMT).
Although considered a relatively peaceful country in a volatile region, Kenya was hit by large bomb blasts in 1998 and 2002 that were blamed on al Qaeda.
If an attack is confirmed, suspicion could fall on militant Islamists from neighbouring Somalia or members of the criminal Mungiki gang wreaking havoc in Kenya for the last month.
The blast occurred during rush hour near the Ambassadeur hotel outside a restaurant in the city's packed central business district. It shattered shop windows and damaged a nearby bus.
Witnesses said the corpse was that of the man seen running.
"We saw a person rushing towards a City Hoppa bus, then it was as if he changed his mind and rushed back," said witness Jane Muna, who added that the man looked Asian or Arab.
"He was carrying a small carton. I think he was trying to run into the restaurant with the box but I saw it explode at the door. I saw about eight people lying on the ground."
Local KTN television, however, said a man carrying a grenade was killed when it exploded as he tried to board a bus going to Nairobi's international airport.
Some torn papers with English and Arabic script from the Koran were found at the scene, witnesses said, and anti-terrorism police arrived quickly.
FLYING GLASS
The blast sent the Kenyan shilling down to 67.15/25 against the U.S. dollar from 66.40/50 on Friday. "The market is anxious about what the bomb portends," said one dealer, Raphael Owino.
At Nairobi's Kenyatta Hospital, where blast victims were distinguished from other patients with a white sticker on their foreheads, staff said 37 people were hurt, four critically.
"The first injuries we received were very bad. Some had deep cuts in their necks caused by glass," a nurse said.
Police Commissioner Hussein Ali berated media for speculation and said it was too early to know the cause.
"Was it something that somebody was carrying?" he said. "We will get to know once have investigated properly."
Taxi driver Bernard Kungu, 36, said he saw six people lying on the ground after the explosion. One had been running down the street just moments before, he said.
"It sounded like a transformer had exploded but then the windows of the shops around me broke and glass was flying everywhere ... My ears are ringing and my eyes are smarting."
Baton-wielding police, some of them on horseback, pushed back a crowd of several thousand people milling round the scene.
The blast came after weeks of violence by the Mungiki, notorious for beheading its enemies. More than 30 people were killed by police last week in raids on a Nairobi slum which is a stronghold of the gang, which has been calling for an uprising.
Tribal and criminal violence traditionally flares ahead of elections, and a presidential poll is due in December.
A bomb killed more than 200 people at the U.S. embassy in 1998 -- just a few blocks from Monday's blast -- and 15 at an Israeli-owned hotel in Mombasa in 2002.
