LOS ANGELES, May 15 (Xinhua) -- Four U.S. citizens, all from Southern California, were found dead in Tijuana, a Mexican town bordering the United States, a newspaper report said on Friday.

    The bodies of two men and two women bore "signs of violence," the Los Angeles Times said, quoting Mexican and U.S. authorities.

    The bodies, which were covered with blankets and had several wounds, were found over the weekend in a car but their identities were not confirmed until Thursday, the paper said.

    A spokesman for the U.S. Consulate in Tijuana confirmed the identities of the dead as Luis Games Chavez, 21; Oscar J. Garcia III, 23; Brianna Hernandez Aguilera, 19; and Carmen Ramos Chavez, 20, according to the paper.

    All were U.S. citizens and Southern California residents, the consulate spokesman said but declined to give specific hometowns or say how long the four had been in Tijuana.

    But Mexican authorities listed Ramos Chavez as a Mexican citizen.

    The circumstances are being investigated.

    Seven police officers were killed in a single day in a series of brazen attacks two weeks ago in Tijuana, once one of Mexico's most violent border cities haunted by drug trafficking.