Israel's 92-year-old former president Shimon Peres has been rushed to hospital with chest pains and has undergone a heart procedure, his spokeswoman said.
Ayelet Frisch told Israel Army Radio that Mr Peres fell ill at home and was sent by ambulance to a hospital near Tel Aviv after a check-up found changes to his heart rate.
In a later statement, Mr Peres's office said he underwent a successful cardiac catheterisation.
"Peres feels well and is fully conscious and his condition is stable," the statement said.
Mr Peres won the Nobel Peace Prize in 1994 after the signing of 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.
The prize earned Mr Peres his stature abroad as a revered statesman.
He completed a seven-year term as president in 2014 and remains in the public eye. He is still active through his non-governmental Peres Centre for Peace, which promotes co-existence between Arabs and Jews and peace and development in the Middle East.
Mr Peres has filled nearly every major position in Israeli public life since he became the director general of the Defence Ministry at the age of 29 and spearheaded the development of Israel's nuclear programme.
A protege of the country's first prime minister, David Ben-Gurion, Mr Peres was first elected to parliament in 1959.
He has since held every major cabinet post - including defence, finance and foreign affairs - and served three brief stints as prime minister.
Mr Peres's personal physician Raphi Walden said he had a "mild heart attack" but that "his condition is excellent" after the operation.
"I would like to calm the people of Israel," Mr Walden told reporters outside the Tel Hashomer hospital. "He feels very well and he is awake. He was awake the whole time and he is only worried about the continuation of his schedule."
Mr Walden said Mr Peres is expected to stay in hospital for "a few days", adding: "We expect that within a short time he will return to normal."