Formal agreements for plans to build a new railway line in East Africa with Chinese help have been signed in the Kenyan capital, Nairobi.

It is to run from Mombasa to Nairobi and will extend eventually to Uganda, Rwanda, Burundi and South Sudan.

In Kenya, the line is to replace a narrow-gauge track built more than 100 years ago during British colonial rule.

China is to finance 90% of the first stage, put at $3.8bn (£2.3bn), with work carried out by a Chinese firm.