CAIRO, JULY 4 -- Iranian President Ali Akbar Hashemi Rafsanjani today called the death of more than a thousand Moslem pilgrims in Mecca "a bitter incident" for which Saudi Arabia "must answer to the Islamic world."

The Iranian leader, making his first comment on Monday's tragedy in which 1,426 pilgrims were crushed or suffocated during a stampede in a pedestrian tunnel, also called on Islamic states to "think up a fundamental solution for running the holy shrines" of Islam, according to Tehran radio.

His remarks appear to indicate that Iran's Shiite Moslem leaders intend to use the disaster, which Saudi officials have stressed was an accident, to fuel their challenge to Saudia Arabia's traditional guardianship of Islam's two holiest cities, Mecca and Medina.

Meanwhile, the Saudi government reportedly has buried the victims in a mass grave near Mecca, according to a foreign official who is attempting to identify his nationals who died.

The official, who asked not to be identified, said his staff was told by a Saudi military officer and doctors that the dead were buried together in a dry river bed. He said he was told the bodies were photographed so that they can later be identified by embassies or relatives.

The mass burial was "understandable," he said, given that there were no facilities to store the large number of corpses and that the government was concerned about the spread of disease in the crowded pilgrimage area, where about 2 million people are congregated and temperatures are well above 100 degrees.

Nevertheless, he indicated he was disturbed that the Saudis had not officially notified his government of the mass burial. Saudi officials could not be reached for comment about the reported mass burial.

Saudi Interior Minister Prince Nayef said Tuesday that the stampede began when several people fell off an overcrowded bridge leading to the tunnel. This caused those on the bridge and in the tunnel to panic and trample others.

He gave no numbers of injured.

Shiite Moslem Iran draws little support from other Moslem countries for its campaign to change the administration of Islam's holy sites.

"It was to be expected that the Iranians would try to make some benefit out of this situation," said an Arab diplomat in Saudi Arabia.

But Saudi officials are resentful of Iran's challenge to their religious leadership, and this will likely be heightened by Rafsanjani's response to the disaster.

Although Saudi Arabia severed diplomatic relations with Tehran two years ago, it sent 20 planeloads of relief supplies to aid victims of Iran's recent earthquake. But it was not among the 98 countries Iran officially thanked for their assistance.