Mr Tsvagirai had only recently returned to work after his wife's death

The four-year-old grandson of Zimbabwe's Prime Minister Morgan Tsvangirai has drowned in a swimming pool at the family's home in Harare.

The death of the child, Sean, comes less than a month after Mr Tsvangirai's wife Susan died in a car crash.

The prime minister had been at a ministerial meeting in Victoria Falls at the time of the drowning, but left to be with his family.

He had only recently returned to work after mourning his wife's death.

Mr Tsvangirai was injured in the March crash that killed his wife of 31 years.

Sean Tsvangirai was the son of the prime minister's second son, Garikai, who lives in Canada but had been in Harare since his mother's death.

Ministers from Zimbabwe's power-sharing government had been meeting for a three-day bonding session in a luxury hotel in the resort of Victoria Falls.

The exercise was intended to help the former rivals trust each other and work together after years of division.

Mr Tsvangirai was sworn in on 13 February as part of a new power-sharing government with President Robert Mugabe.

The unity government is tasked with reversing years of economic decline in the country.