The military-led government in Chad says 50 people have been killed and more than 300 others wounded in a day of protest demanding a transition to democracy.

Newly appointed Prime-Minister Saleh Kebzabo says some of the protesters were armed.

Among those killed were members of the security forces. The government has announced a curfew in the capital and two other towns affected by the protests.

The authorities say an investigation will be launched. An opposition leader told the BBC the protests would continue until the demands of the demonstrators are met.