People pray during a rare "ring of fire" solar eclipse in Surabaya, Indonesia on Thursday. Photo: AFP

Skywatchers from Saudi Arabia and Oman to India and Singapore were treated to a rare "ring of fire" solar eclipse Thursday.

Annular eclipses occur when the moon is not close enough to the Earth to completely obscure the sun, leaving a thin ring of the solar disc visible.

While these types of eclipses occur every year or two, they are only visible from a narrow band of the Earth each time and it can be decades before the same pattern is repeated.

Depending on weather conditions, this year's astronomical phenomenon was set to be visible from the Middle East across southern India and Southeast Asia before ending over the northern Pacific.

Hundreds of amateur astronomers, photographers, including observatory arrangements by Singapore's harbor for what some described as a "once in a lifetime" event, were in place. 

"The next one will happen in about 40 years I think," said Jason Teng, 37, who took the day off work to photograph the eclipse.

The amateur astronomer used a special solar filter on his telescope as there is no safe ­period to observe an annular solar eclipse.

Alexander Alin, 45, a geophysicist from Germany, travels around the world following eclipses. "It's only two minutes, but it's so intense that you talk about it with your friends, ­family for the next month," Alin said.

In southern India, people gathered on the beaches in Tamil Nadu to watch the event.

The eclipse even affected cricket, with play delayed by two hours in a first-class match between Mumbai and Rajkot.

The eastern state of Odisha declared a public holiday, with all government offices, courts, schools and colleges closed.

But in New Delhi, cloud and pollution blocked the view and Prime Minister Narendra Modi tweeted his disappointment, although only a partial eclipse would have been visible that far north.

"Like many Indians I was enthusiastic about #solar­eclipse2019," Modi wrote.

"Unfortunately, I could not see the sun due to cloud cover but I did catch glimpses of the eclipse in Kozhikode and other parts on live stream."

Outside the narrow band where the "ring of fire" effect can be observed, skywatchers would see a partial solar eclipse.

The next annual eclipse in June 2020 will be visible to a narrow band from Africa to northern Asia.

The following one in June 2021 will only be seen in the Arctic and parts of Canada, Greenland and the remote Russian Far East.