( CNN ) -- Mexico 's foreign ministry has accused a U.S. Border Patrol agent of fatally shooting a Mexican citizen along the border . The shooting occurred Monday after agents in the area of Laredo , Texas , `` were subjected to rocks being thrown at them from the Mexican side of the Rio Grande River , '' the patrol 's Laredo sector said Thursday . `` A weapon was discharged by Border Patrol . All appropriate authorities were notified and the shooting is under investigation by the Federal Bureau of Investigation , '' the statement said . The U.S. statement did not specify whether a death occurred . Mexico 's foreign ministry said a Mexican national died after being shot by a U.S. agent between Laredo and Nuevo Laredo , Mexico . The ministry did not release details about the circumstances surrounding the Monday violence . `` The Mexican government has repeatedly expressed that the disproportionate use of lethal force in the exercising of immigration control functions is unacceptable under any circumstance , '' the foreign ministry said Wednesday , calling for a thorough investigation . The Mexican foreign ministry released a similar statement in July , after it said that a U.S. Border Patrol agent had killed a Mexican citizen near the bridge between Matamoros , Mexico , and Brownsville , Texas . At the time , a U.S. Customs and Border Protection spokesman said two agents fired shots during `` dangerous encounters '' along the border . CNN 's Mariano Castillo contributed to this report .
Border Patrol says rocks were thrown at its agents . Mexico 's foreign ministry criticizes `` disproportionate use of lethal force '' The FBI is investigating .