The death toll from mysterious lung illnesses linked to vaping across the U.S. has risen to 37, according Thursday to the nation's health protection agency.

Axar.az reports citing Anadolu Agency.

The cases of vaping-related illnesses jumped to 1,888, said the Centers for Disease Control and Prevention (CDC) in a statement.

Last week, the agency verified more than 1,600 confirmed and probable cases in 49 of the U.S.'s 50 states. Alaska is the sole exception.

Officials are continuing to search for a cause for the outbreak.

Most of the affected patients reported vaping THC, the psychoactive ingredient in cannabis, though investigators have yet to officially determine a cause for the illnesses that have included problems breathing, chest pains and vomiting.

The CDC recommends people to not use e-cigarettes or vaping products that contain THC and not to modify products purchased through retail establishments.