About 60 people were injured when Indian police used batons to push back hundreds of Nepal-based Bhutanese refugees who were trying to enter India and then return to Bhutan, police and witnesses said on Saturday.
About 100,000 ethnic Nepali Bhutanese have been living in camps in eastern Nepal on the border with India since Bhutan's king stripped them of citizenship or forced them to leave after they campaigned for democracy in the early 1990s.
On Saturday, around 1,000 of them gathered on the India-Nepal border for a meeting to mark the Bhutanese National Day, but later tried to force their way into India.
The refugees have to travel through India's West Bengal state to reach Bhutan from eastern Nepal.
"We had to use batons to stop them," police spokesman S.P. Mishra told Reuters from Siliguri, about 650 km (400 miles) north of the state capital Kolkata. "They turned violent and pelted us with stones." The skirmishes left about 60 people injured, some of them requiring hospitalisation. The organisers of the rally denied they were violent.