The Mexican officials have urged more study of the issue.

At the same time, public officials were urging people to go about their normal lives during the holiday season.

In some cases, elected officials have even urged universities to take strong action.

Officials urged anyone who sees the barrels to report them to the police and to keep their distance.

Other officials also urged caution but said there was no specific information about a terrorist attack.

Officials urged people not to panic, and a national emergency task force was established.

Officials urge businesses in the area to close and public transport is suspended.

Officials urged residents not to touch anything odd found in their boxes.

American officials in Washington urged caution, however, saying the factions were far from a real peace agreement.

On radio and television, public officials urged residents to bide their time for a few more days.