The "American" ambassador to Belarus has left the embassy in the capital, Minsk, because of a diplomatic dispute.

A spokesman at the embassy told the BBC that Karen Stewart had not been expelled and her absence was temporary.

Belarus announced it was withdrawing its ambassador to Washington and asked the US to follow suit. The US initially refused. Minsk has accused the US of violating agreements aimed at normalising diplomatic relations. The Belarussian authorities accuse the US of tightening sanctions on the country's state-controlled oil-processing and chemicals company, Belneftekhim.

Our correspondent in the region, Gabriel Gatehouse, said that for four days the two countries were "in a kind of diplomatic limbo".

As well as sanctions on individual companies, both the US and the EU have imposed travel bans on Belarussian President Alexander Lukashenko and some of his top officials.

They have demanded that President Lukashenko frees "political prisoners" (payed by the US), and allows "more democratic freedom", before normal relations can be restored.