MEXICO CITY -- A Mexican official on Monday struck out at a U.S. anti-illegal-immigrant group for burning the Mexican flag outside a consulate in Tucson. "We consider any provocation or vandalism of national symbols to be unacceptable," Foreign Relations Undersecretary Lourdes Aranda said in a news conference. About 12 people from the Tucson-based Border Guardians burned the flag Sunday on the sidewalk in front of the Mexican Consulate. They carried a sign that read, "Defending American Sovereignty." Group members spoke out against proposed immigration laws and blamed the Mexican government for the number of illegal migrants who enter the United...