Former Israeli Prime Minister Ehud Olmert has been ordered to serve 18 months in jail for bribery.

Olmert had been sentenced to six years by a lower court in 2014, but this was reduced by the Supreme Court.

The 70-year-old was convicted over a real estate deal that took place while he served as mayor of Jerusalem, prior to becoming prime minister in 2006.

Olmert, who stepped down in 2009, will become the first former Israeli head of government to go to prison.

He is also appealing against a conviction for fraud and breach of trust.