But officials have said nothing to suggest they suspect foul play. Tsvangirai has previously spent time in Botswana while in opposition, according to BBC
He returned from Botswana to Zimbabwe on 17 January this year, having spent much of the previous two months away.

The source who spoke to the BBC said the prime minister's departure from Zimbabwe was not because of security concerns.

Head injuries

Tsvangirai, 56, on Saturday afternoon left the Harare clinic where he was treated for head and neck injuries sustained in the crash the previous day.

The AFP news agency quoted an MDC spokesman as saying: "I do not know when he will be back, he will undergo a check-up, but he is out of danger now."

Tsvangirai was on his way to his rural home in Buhera, where he planned to hold a weekend rally, when the crash occurred near Beatrice at about 1600 local time (1400 GMT) on Friday.

Police said a lorry carrying freight crossed into the lane in which the prime minister's 4x4 was travelling and side-swiped the vehicle, causing it to roll over three times.
US embassy officials said the lorry belonged to a partner organisation of the US government aid agency USAID.

The UK Foreign Office confirmed on Saturday that the lorry was operated by a project jointly funded by the US and UK.

"All indications are that this was a genuine accident," a Foreign Office spokeswoman said.

Tsvangirai and his wife Susan, 51, who married in 1978, had six children.

Friends and relatives gathered at the Tsvangirai family home on Saturday to console one another for her loss.