Mexican-American singer Jenni Rivera is feared dead, as the small plane she was traveling in with at least five others crashed in the mountains in northern Mexico.

Authorities have notified the family there were no survivors, the singer's brother, Gustavo Rivera, has told CNN.

There were conflicting reports about the number of people onboard the plane that took off early Sunday from Monterrey, Mexico, and lost contact with air traffic controllers a short time later.

Gustavo Rivera has told CNN that there were six people onboard, including Jenni Rivera, her publicist, her lawyer, a family friend and two pilots. Rivera's father, according to published reports, said there were up to seven people on the plane, though he did not identify those believed to be onboard.