UK Prime Minister Theresa May is to announce a tie-up with the Kenyan authorities to help track down British paedophiles as she concludes her tour of Africa.

The UK is to build a cyber centre in Nairobi to help Kenyan police stop child abuse images being shared online.

It will also assist efforts to identify potential victims and access data from tech firms to catch offenders.

Mrs May is the first British prime minister since Margaret Thatcher in 1988 to visit the country.

She is to meet president Uhuru Kenyatta and see British soldiers who are training troops from Kenya and other African countries fighting Islamist militant group al-Shabaab in Somalia.

The prime minister will announce a wide-ranging new security pact between the two countries, including funding for enhanced airport security in the former British colony.