Relief at the naming of a new coalition government in Kenya has been tempered by disappointment in the large size of the cabinet and an acknowledgment of the steep challenges facing the country. A stark reminder of the potential for unrest was provided by a series of attacks, in and around the capital, by a notorious criminal gang. Derek Kilner reports from Nairobi.

After weeks of wrangling, Kenya's leaders have announced a coalition government, with opposition leader Raila Odinga named to serve as prime minister alongside his opponent in December's disputed elections, President Mwai Kibaki.

Editorials in Kenya's main newspapers welcomed the end to the impasse, but were quick to move on to the need for action on the challenges facing the country, including the resettlement of the hundreds of thousands displaced by post-election violence, and the reform of Kenya's constitution.

Many Kenyans have also been disappointed by the decision to increase the size of the cabinet to 40 ministries, arguing that it is a waste of government resources.

Cyprian Nyamwamu, the leader of the National Civil Society Congress, a coalition of non-governmental organizations, criticized the announcement.

"This is the largest cabinet ever on the African continent," said Cyprian Nyamwamu. "There is no reasonable explanation why a country as poor as ours that cannot even feed its people should have a cabinet of more than 24 ministries."

The new positions include a Minister for Development of Northern Kenya and Arid Lands and a Minister for Nairobi Metropolitan Development. A Minister for Medical Services and a Minister for Higher Education, Science and Technology have been added to the existing health and education ministers.

But Foreign Minister Moses Wetangula, who belongs to the president's Party of National Unity, defended the size of the cabinet.

"The price we had to pay for unity of the country is much more important than the size of any cabinet," said Moses Wetangula. "If we are talking of grand coalitions, then you are bringing in a multiplicity of parties and interests and regions and so on, then you invariably will have a much larger cabinet than is normal."

Meanwhile, members of the notorious Mungiki gang blocked roads and set fire to vehicles in Nairobi and the nearby town of Naivasha, closing one of the main highways out of the capital and killing at least nine people.

The group draws its members from President Mwai Kibaki's Kikuyu tribe - Kenya's largest ethnic group.

The gang has developed into an organized crime syndicate in recent years, and is suspected of links to Kikuyu politicians. Last year, the group was blamed for a crime wave that included a series of beheadings.

The latest episode is thought to be a reaction to the killing Thursday of the wife of Mungiki leader Maina Njenga, and not directly related to wider political developments. The Mungiki are one of the main groups suspected of post-election tribal violence, particularly around the Rift Valley towns of Nakuru and Naivasha.

Police said they have arrested several members of the group. The police operation targeting last year's crime wave came under fire from human-rights groups that accused the police of widespread extra-judicial killings.