American and Georgian security officers are investigating how an unarmed grenade came to be found near the site where President Bush Tuesday delivered an address before a packed crowd on Tbilisi's Freedom Square.

Georgian President Mikhael Saakashvili and his wife Sandra Roelofs stand during the U.S national anthem with U.S. President George W. Bush and first lady Laura Bush

A top Georgian security official has confirmed reports of a grenade being found within 30 meters of the podium from which President Bush and Georgian President Mikhail Saakashvili addressed the crowd.

But the secretary of Georgia's National Security Council disputes reports that the pin had been pulled on the grenade and that it had been thrown. He says it was found inactive and that there apparently was no intention of harming anyone.

All the same, agents from the Georgian and American security services will be looking into how the grenade happened to be so close to the podium, despite tight security and weeks of advance preparation.

President Bush returned to the United States, late Tuesday, completing a five-day European tour that also took him to Latvia and Russia.