A total solar eclipse began its flight on Wednesday across a narrow swathe of Asia, where hundreds of millions of people watched the skies darken despite thick summer clouds.

The longest total solar eclipse of the 21st century was visible along a roughly 250 km-wide (155 miles) corridor, according to the U.S. space agency NASA, as it travelled half the globe and passed through the world’s two most populous nations, India and China.

As dawn broke on Wednesday, the century’s longest total solar eclipse began with thousands of sky gazers craning their neck skywards to catch the glimpse of the rare celestial spectacle.

The sun rose eclipsed on Wednesday morning at 5:28 a.m. at a local sunrise point in the Arabian Sea close to the western coast of India near Surat in Gujarat.

In India, the totality phase will last for some 3 minutes 30 seconds and places like Surat in Gujarat, Indore and Bhopal in Madhya Pradesh, Varanasi in Uttar Pradesh and Patna and Taregna in Bihar will observe the total solar eclipse.

The total eclipse will be between 6:20 a.m. to 6:25 a.m. when sun will be completely obscured by the moon.