LHASA -- Tibetans lit butter lamps and prayed through the night in an annual festival commemorating Tsong Khapa, a master of Tibetan Buddhism.

At 4 pm on Friday, monks gathered for prayers at the Jokhang Temple in the heart of Lhasa, capital of Southwest China's Tibet autonomous region.

Thousands of pilgrims and believers gathered around the temple to join the prayers.

More than 8,000 butter lamps were lit on top of the temple building, in prayer halls and in monks' residences.

"Ganden Atsok" is celebrated on the 25th day of the tenth month according to the Tibetan calendar, when Tsong Khapa, the founder of the Gelupga, the "yellow sect" of Tibetan Buddhism, passed away in 1419.

Monks chanted sutras in his praise. Believers prayed for happiness and good health.

Yangdron, a Lhasa resident, lit 108 lamps at her home. "I started to melt the butter two days before the festival. It is an important day," she said.

On Friday, similar ceremonies were held in monasteries at Sera and Zhaibung, also in Lhasa.