BEIJING — Authorities in Tibet have detained 59 people accused of disseminating rumors aimed at inciting ethnic tension and have cracked down on illegal downloads of "reactionary music" online, Chinese state media reported Thursday.

Law enforcement officers have found 48 cases of "rumor spreading" since March, when anti-government riots rocked the Tibetan capital Lhasa, a report by the China Tibet News said, citing a local public security official.

Xin Yuanming, deputy chief of the Lhasa public security bureau, said those being investigated were instigated by the Dalai Lama, Tibet's exiled spiritual leader, according to the report. It did not name those detained nor give other details.

The rumors posed a threat to public security by fanning ethnic hatred and damaging the image of China's ruling Communist Party, the report said.

Beijing says the March protests were part of a violent campaign by the Dalai Lama and his supporters to overthrow Chinese rule in Tibet. The Dalai Lama, a Nobel Peace Prize laureate, has denied involvement in violence and says he only wants greater autonomy for the remote Himalayan region.

Xin also said authorities have also cracked down on the downloading and selling of music it called "reactionary." The report said that unnamed people were downloading such music from the Internet onto compact discs and digital formats for public sale.

Xin said five people found selling "reactionary music" have been detained since Dec. 4, the report said. He said investigations were ongoing.

Tibetans across western China exploded in the largest uprising against Chinese rule in nearly 50 years in March. China responded to the deadly riots with a massive crackdown in Tibet and the surrounding region in which exile groups say at least 140 people were killed and more than 1,000 were detained.

Last month, state media reported that the Chinese government sentenced 55 people in connection with the March unrest, but did not say what charges they were convicted on and what sentences they received.

China maintains that Tibet has been part of its territory for more than seven centuries and denounces the Dalai Lama as a separatist.

Many Tibetans say they were effectively an independent country for most of that time. The Dalai Lama has lived in exile in India since fleeing Tibet amid an abortive uprising against Chinese rule in 1959.