Shimon Peres is being treated in hospital for a hernia.

The Israeli President, 89 in August, was in Canada this week on a state visit, and returned earlier today. On arrival in Tel Aviv he was admitted to the Sheba Medical Centre to undergo surgery.

His spokeswoman, Ayelet Frisch, said that Mr Peres's son-in-law and personal doctor Rafi Walden found the hernia earlier in the week, but the president opted to continue with the trip.

She said he was "feeling fine" when she spoke to him before the operation.

It means that the president will most likely be unable to present the Wolf Prize at a ceremony at the Knesset on Sunday. The prestigious award, worth $100,000, is given annually to people who have excelled in the arts and sciences.

During his stay in Canada Mr Peres spoke warmly of ties between the two countries and expressed gratitude for 60 years of friendship. "Canada is always positive, never indifferent, never neutral," he said.