BANGKOK -- Thai authorities on Monday were investigating an after-hours fire that roared through Bangkok's Chatuchak weekend market, destroying scores of small shops crammed inside one of Asia's most popular bazaars.

The Thai capital's fire emergency service said the blaze started after 9 p.m. Sunday and affected more than 100 stalls spread across about 1,000 square meters (10,764 square feet). No injuries were reported.

The sprawling and densely packed Chatuchak market sells a wide variety of goods in its thousands of stalls, from clothing and handicrafts to paintings and live animals. It is popular with locals and tourists alike.

"The fire was just too big. People were evacuating their shops," said eyewitness Younes Parvin, a university student who shot cellphone video of the blaze from about 20 metres (yards) away. "It was quite terrifying."

Parvin said it took firefighters 10 minutes to arrive, and that eventually dozens of emergency vehicles were on the scene. Most shops had closed by the time the fire started and vendors were heading home, he added.

"If it was daytime ... it would have been a lot worse," he said.

The packed market, which is covered in most parts, is crisscrossed by narrow and often crowded passageways that can be dizzyingly disorienting for first-time visitors.

Aswin Kwanmuang, Bangkok's governor, said some 110 vendors were affected by the blaze and vowed to provide compensation to those affected. He speculated that an electrical short circuit could be to blame given that the electrical system in the market is about three decades old. Rebuilding of the affected portion of the market was expected to take two months.

Video posted by social media users showed intense flames raging from the single-story market as onlookers watched nearby.