Former Israeli President Shimon Peres is in intensive care after suffering a serious stroke, medical officials say.
Doctors at the Sheba Medical Centre near Tel Aviv, where he is being treated, said Mr Peres was “in a critical condition but stable”.
The 93-year-old is in an induced coma and is breathing with the help of a respirator.
In January, he underwent successful minor surgery at the same hospital after suffering a small heart attack.
The stroke had caused “lots of bleeding”, the head of the medical centre said.
The former president’s son, Chemi, said the family was going through some “difficult hours”.
“I’m optimistic. I’m a great believer in my father. He’s a unique person. And I pray with all my heart, together with my family, that things will improve from this point on,” he said.
“Shimon, we love you and the entire nation is wishing for your recovery,” Prime Minister Benjamin Netanyahu tweeted.
The veteran politician has held almost every major political office since Israel was founded in 1948, and was the architect of Israel’s secret nuclear programme.
He twice served as prime minister and was president from 2007 to 2014.
He won the Nobel Peace Prize in 1994 for his role negotiating the Oslo peace accords with the Palestinians a year earlier, a prize he shared with Prime Minister Yitzhak Rabin, who was later assassinated, and Palestinian leader Yasser Arafat.
Despite his age, Mr Peres has maintained an active public schedule, mostly through his non-governmental Peres Centre for Peace, which promotes closer ties between Israel and the Palestinians.
Hours before his hospitalisation, Peres uploaded a video to his Facebook page urging people to buy local products.
When leaving hospital after his heart treatment in January, then 92-year-old Peres told reporters he was “so happy to return to work, that was the whole purpose of this operation”.