The military in Chad has announced that elections will be held in 18 months' time, following the death of President Idriss Déby.

The government has been dissolved and Mr Deby's 37-year-old son Mahamat Kaka, a four-star general, has been named interim president.

Experts have told the BBC and other broadcasters that the move is unconstitutional and that the speaker of parliament should take over when a sitting president dies before organizing elections.