Pope's Balkans tour overshadowed by new security fears

Pope John Paul II returns to Rome today after a gruelling five-day tour of Croatia in broiling temperatures, which his press spokesman conceded had been "very stressful". The pontiff recently turned 83 and has Parkinson's disease, and crippling knee and hip problems. Last month, after a hiatus of nearly a year, he visited Spain for the fifth time.

This is his third trip in nine years to Croatia, an overwhelmingly Catholic country with special importance for the Pope because of its war and its border with Orthodox Serbia and Muslim Bosnia. As on all his tours, he was greeted everywhere by massive, ecstatic crowds. But temperatures in the high 30s killed two people and put 150 in hospital.

And on Friday, two Croatian news agencies received e-mails threatening to assassinate him in Croatia. The messages were titled "Message to Infidels" and sent "in the name of Allah", and signed "el-Mujahedin Islamic Front". The Interior Ministry said they had a Bosnian address.

But the Pope's press spokesman, Joaquin Navarro-Valls, said: "It's not unusual during the Pope's trips that there are warnings or rumours of potential assassination attempts. The credibility of the information is often very doubtful or completely false."

Tour security has been tight. In Rijeka on the Adriatic coast, once part of Italy and known as Fiume, where the Pope celebrated Mass yesterday, there was a heavy police presence and helicopters made low sweeps over the city.

Today, before heading back to Italy, he will end his tour with a visit to the southern coastal city of Zadar. Even by this Pope's extraordinary standards it has been a gruelling trip. Wailing ambulance sirens shattered the calm of Saturday's Mass in the eastern city of Osijek as worshippers struck down by the ferocious heat were taken to hospital. But although the Pope sat slumped in his chair at times, and at the end of the Mass briefly buried his head in his hands, he soldiered on. Yesterday, as the heat wave continued with temperatures in the mid-30s, the Pope looked uncomfortable in his heavy crimson robe. But he seemed more rested during a visit to the Croatian shrine of Trsat in the evening.

"He is amazing," Mr Navarro-Valls said. "What you can see everywhere is the inner strength of this man who keeps going without even asking, 'Am I tired? Is this too much?' He just keeps the pace, the pace he has imposed on himself."

On 22 June, the Pope is planning a one-day visit to Bosnia. But Vatican officials have been casting doubts on whether he will visit Mongolia in late August. The Vatican also has been hoping that John Paul could be the first Pope to make a stop in Russia then.

The Russian Orthodox Church has been opposed, accusing the Vatican of trying to expand its influence in traditionally Orthodox lands.

* Police had to stop angry Croats attacking French actors simulating sex outside the cathedral in the capital, Zagreb, during the papal visit to the former Yugoslav republic, the daily newspaper Jutarnji List reported yesterday.