(Reuters) - U.S. health officials on Thursday reported 26 deaths and 1,299 confirmed and probable cases so far from a mysterious respiratory illness tied to vaping.

FILE PHOTO: A man holds an electronic cigarette as he vapes at a Vape Shop in Monterrey, Mexico February 1, 2019. REUTERS/Daniel Becerril

Last week, the Centers for Disease Control and Prevention (CDC) reported 1,080 cases and 18 deaths from the illness.

As of Oct. 8, confirmed deaths were reported from 21 states, including one each from California, Connecticut, Georgia, Massachusetts, Michigan, New York, Texas and Pennsylvania.

Investigators have not linked the cases to any specific product or compound, but have pointed to vaping oils containing THC, the psychoactive ingredient in marijuana, as being especially risky.

The serious respiratory illness has prompted a health scare that has led U.S. officials to urge people to stop vaping, especially products containing THC.

Doctors studying lung tissue samples from people with vaping-related injuries have found that none of the cases had evidence of lipoid pneumonia, a rare diagnosis typically linked with people accidentally inhaling oils into their lungs.

As the outbreak picks up pace, some states, including New York, Michigan and Rhode Island, have banned the sale of flavored e-cigarettes.

Massachusetts has gone a step further by imposing a four-month ban on all vaping products and a federal judge last week denied an industry bid to put the ban on hold.

Chinese e-commerce firm Alibaba Group Holding Ltd said on Wednesday it will stop the sale of e-cigarette components in the United States, joining retailers Kroger Co, Walgreens Boots Alliance Inc and Walmart Inc that have moved to stop the sale of the devices.

In addition, Washington state Governor Jay Inslee has urged state agencies to ban flavored and cannabis-derived vaping products.