Activists initially claimed one person was killed in police firing. But the police denied both the claims - of firing and fatality. Later in the evening, Gorkha Janmukti Morcha leaders said two supporters were seriously injured.
"We condemn the police action on a democratic protest in a democratic country," Morcha chief Bimal Gurung said in a statement.
Police used water cannons, batons and teargas to disperse the protesters allegedly trying to march to Siliguri town, 12 km away.
Gorkha Janmukti Morcha activists have been demonstrating across the hills daily for Gorkhaland but there was no confrontation with police.
Today, however, when they marched with kukris towards Siliguri, official sources said police had to step in. Had the protesters managed to reach Siliguri, the situation could have deteriorated rapidly.
At Sukna, police managed to push protesters back some distance. But till 8 pm at least, stone throwing continued. Protesters were using catapults to hurl stones at the police. A senior officer said several police personnel had been injured in the stone throwing.
Some reports said 'petrol bombs' - bottles filled with petrol, plugged with cloth and set alight - were also used.
Last week West Bengal Chief Minister Mamata Banerjee met home minister Rajnath Singh in New Delhi and discussed the Darjeeling situation. Details of the meeting are not known.
Tomorrow, 30th July, supporters of 'Gorkhaland' across the world are planning to march for a separate state. A campaign has been launched on social media called 'Global Gorkhaland Unity March'.
Meanwhile in the hills, 12 people are on hunger strike for the ninth day - three each at Darjeeling, Mirik, Kurseong and the neighbouring district of Kalimpong.
The district magistrate of Darjeeling warned yesterday that if anyone tries to stop the government from giving the people on hunger strike medical assistance or remove them to hospital, they could be punished for "abetment to suicide and... murder with life imprisonment."