The military is reportedly just hundreds of meters from the city's ancient sites.
The pop star, 21, was asked to leave a Mayan site in Tulum, Mexico.
The Islamic State militant group demolished artefacts for "idolatry" in Palmyra in 2015.
A shipment of a few hundred small clay tablets from Iraq in 2011 might have been illegal.
Archaeologists believe the discovery could lead to an ancient ritual site, or the tomb of a king.
Zeno, Epictetus, Seneca and Marcus Aurelius, the great Stoic philosophers of the classical world, are back in vogue
While they were excavating a tomb in northern Greece, a 10-by-15-foot mosaic appeared
Two "matching" towns from the Basketmaker period were discovered in neighboring sand dunes