At least six people have been killed and up to 25 injured after three bombs were thrown in a busy part of the predominantly-Somali area of Kenya's capital, Nairobi.

The blasts on Monday targeted roadside food stalls and restaurants in the Eastleigh suburb of the city, known as "Little Mogadishu" for its large immigrant population.

The first hit a roadside where women were selling food. Two more were thrown into separate restaurants. Most of the victims were believed to have died in one of the restaurants.

No group or individual has claimed the attacks. However in the past, such attacks in the area have been blamed on Somalia's al-Shabab armed group.

Benson Kibue, Nairobi's police commander said: "I want to assure all Kenyans that we are doing everything we can and that they are safe, we are securing everything."

Kenya's president, Uhuru Kenyatta, is under increasing pressure to secure the capital, scene of the Westgate Mall attack last year claimed by al-Shabab, which left 67 people dead.

Al-Shabab has targeted Kenya after the government sent troops into Somalia to fight alongside government forces there.

Al Jazeera's Tania Page, reporting from Nairobi, said the city had grown more tense in the last week after the government ordered all refugees, most of whom are Somali, to leave urban areas and head to two designated refugee camps.

The order followed the deaths of six people in a gun attack on a church service a week ago in Mombasa.

"The government says that's because some of the people responsible for recent attacks have been refugees," our correspondent said.

"The people of Eastleigh argue they are suffering collective punishment for the actions of a few," she added.