Scores of demonstrators defied a coronavirus lockdown to burn effigies of India's Prime Minister Narendra Modi and his Nepali counterpart, K.P. Sharma Oli, at several protests in Kathmandu.
Protesters say the government has not done enough to counter the Indian project.
Police said at least 30 people were detained.
Foreign minister Pradeep Gyawali summoned Indian ambassador Vinay Mohan Kwatra to hand over a protest note over the road, foreign ministry spokesman Bharat Raj Poudyal said.