Nuevo Laredo (Mexico):
An explosive device went off outside the US consulate in Nuevo Laredo, in northeastern Mexico, with no immediate reports of injuries but some material damage, federal prosecutors said.
"There was an explosion just outside the US consulate in Nuevo Laredo... It apparently was a homemade device" that went off shortly after midnight," a spokesman from the prosecutors' office said.
The US diplomatic office was to remain closed on Monday as the investigation into the explosion continues.
Federal authorities did not name possible motives or suspects. There has been a wave of violence in recent weeks blamed on a split between leaders of the Gulf cartel and the Zetas, former elite troops operating in the area.
The attack comes a month after the Aztecas gang in Ciudad Juarez was blamed for almost simultaneous assaults in which a US consulate worker and her husband, both Americans, were killed, as was a Mexican man who was married to another consulate staffer.
Meanwhile, in Morelia, a journalist and university professor from Michoacan, Enrique Villicana Palomares, was killed on Saturday, prosecutors said. He had been kidnapped and his abductors were seeking ransom.
Mexico has been gripped in drug-related bloodshed since President Felipe Calderon launched a military clampdown on the country's powerful drug gangs after taking office in December 2006.
More than 15,000 people have since died in suspected drug-related violence, particularly near the US border.