By Drazen Jorgic and Humphrey Malalo
NAIROBI, May 16 (Reuters) - Back-to-back explosions killed at least 10 people in a packed Nairobi market on Friday, extending a spate of attacks that have piled pressure on the government and spurred Britain and other Western nations to warn citizens about travelling to Kenya.
Close to 70 people were wounded in the two blasts, Kenya's National Disaster Operations Centre (NDOC) said, and the Kenya Red Cross appealed for blood donations to help the injured.
One explosion struck a minibus taxi, shattering the windows and flattening its tyres. It was near a market best known for selling second-hand clothes from wooden stalls with corrugated iron roofs. The second blast occurred near the same market.
Outside the blood-spattered minibus, clothes littered a street that had been bustling with shoppers earlier in the day.
"I saw the explosion. People were running in all directions," a woman at the scene told journalists. "I know some of the people who died."
Nairobi County Police Commander Benson Kibui told journalists that one suspect was arrested near the market and another was detained elsewhere, without giving details.
There was no immediate claim of responsibility.
In the past such attacks have been widely blamed on the Somali Islamist militant group al Shabaab, which wants Kenyan troops out of Somalia. In September, gunmen from the group killed 67 people in an raid on a Nairobi shopping mall.
Kenya, an important Western regional ally, has suffered a string of bomb and gun attacks since its troops entered Somalia to battle al Shabaab, which had carried out cross-border raids and kidnappings in Kenya.
Many of the attacks have been along Kenya's Indian Ocean coast, including the port of Mombasa, a tourist favourite. Some others have been in Nairobi, mainly near the Somali-populated Eastleigh district. Friday's blasts were close to Eastleigh.
Tourism in the east African nation had already been damaged by kidnappings by Somali pirates in the north near the Somali border, though that threat has subsided over the past 18 months.
Kenyan authorities had hoped for a respite to rebuild the struggling industry.
One immediate commercial victim of Friday's bombings was a regional telecoms conference, East African Com, due to be held in Nairobi next week. Organisers said security worries forced it to cancel the meeting, which attracts top industry executives.
The latest blasts came a day after Kenya rebuked Britain, the United States, France and Australia for issuing travel warnings. Hundreds of tourists have left resorts on the Indian Ocean coast ahead of schedule as a result.
"Yesterday night, 282 tourists flew out and today 300 more are going away," Sam Ikwaye, of the Kenya Hotel Keepers and Caterers, told Reuters in Mombasa, one of several areas the British government said tourists should avoid or leave.
Diplomats have privately said Kenya's security forces have been hampered in their work by inter-agency rivalries in the past and also say the government has not done enough to reassure Kenyans and others that it is stepping up security in the wake of the Nairobi Westgate shopping mall assault.
The government says it has not been credited for all the attacks it says it has foiled, but instead is criticised for the few that get through.
President Uhuru Kenyatta urged Kenyans to help the government in its battle against "terrorism" and dismissed the Western travel warnings as steps that "only strengthen the will of terrorists" instead of helping Kenya defeat them.
"Terrorism is not an evil that was born in Kenya. Terrorism is a worldwide phenomenon," Kenyatta told a previously planned news conference held soon after the latest explosions.
Kibui said the blasts were caused by a Improvised Explosive Device (IED), a reference to a hand-made bomb.
Seven people were killed two weeks ago when explosions struck Nairobi and Mombasa. (Additional reporting by James Macharia in Nairobi, George Obulutsa and Joseph Akwiri in Mombasa; Writing by Drazen Jorgic; Editing by Edmund Blair/Mark Heinrich)