Important Palestinians were called to the 75-year-old's bedside, and his wife Suha is expected to arrive later on Thursday from her home in Paris.

He has apparently been suffering from stomach pains for over a week.

Israeli troops surround the compound in Ramallah where he lives, and if he leaves it to get medical treatment, they might not let him back in.

But an official told reporters that was a separate issue to think about after he gets better.

It's not clear who would take over if Mr Arafat had to quit as head of the Palestinian Authority.

He is the most popular Palestinian leader, and many see him as a symbol of their struggle with the Israelis.

He's been forced to stay in his compound on the West Bank since 2001.