Two explosions have killed at least 10 people in Kenya's capital, Nairobi, according to the country's National Disaster Operations Centre.

One blast on Friday targeted a 14-passenger vehicle that Kenyans use for public transport, the disaster centre said.

Another explosion occurred in Gikomba market, located to the east of the capital's central business district.

"Very many people are injured. I don't know how many are dead but for sure there are fatalities," said Mwangi Maina, a trader who was selling second-hand shoes at Gikomba Market.

The Kenyan Red Cross said that five of its ambulances were evacuating casualties from the blast sites and that more than 10 people were hospitalised.

A spokesman for the Kenyatta National Hospital, Nairobi's main hospital, told the AFP news agency that eight bodies were brought to the hospital and "more than 70" people admitted for treatment, many of them in a serious condition.

"Many of the injured are bleeding profusely. We need a lot of blood," said Simon Ithae, the spokesman.

The bombings came amid a wave of attacks in Nairobi and the port city of Mombasa.

Several countries issued new travel warnings for Kenya and hundreds of British tourists were evacuated from resorts near Mombasa on Thursday and Friday.

Three people were killed and 86 other people were injured in twin bus blasts in Nairobi earlier this month that were blamed on groups connected to the al-Qaeda-linked, Somali-based group, al-Shabab.

The US embassy said that more than 100 people have been killed in shootings, grenade attacks and small bombs in Kenya over the past 18 months.

No one has claimed responsibility for Friday's attacks.

Source: Agencies