A prominent tribal leader of the movement against proposed bauxite mining in Niyamgiri hills in Orissa's Kalahandi district has been missing under mysterious circumstances since Monday afternoon. 

Prominent social activists and those leading the agitation against Vedanta's mining plan alleged on Wednesday that tribal leader Lado Sikaka was abducted at gunpoint by persons who claimed to be police personnel. 

The incident comes when Vedanta's mining plans are under the scanner of the Union Ministry of Environment and Forests.  

President of Lok Shakti Abhiyan, Orissa unit, Prafulla Samantara alleged that Lado Sikaka, a member of the primitive Dongria Kondh tribe and leader of the Niyamgiri Suraksha Samiti (NSS), was abducted from Ijrupa near Lanjigarh in Kalahandi district. Another NSS leader Sana Sikaka too was abducted along with him.

The incident came to light when an injured Sana Sikaka managed to reach his village and narrated the incident, Mr. Samantara said.  

Kalahandi district police said Lado Sikaka was arrested by a team of policemen from the neighbouring Rayagada district. However, the Kalahandi Superintendent of Police Sudha Singh later said the Rayagada police only made an attempt to arrest him in connection with a few pending cases. She said police located Lado Sikaka at the residence of a relative in a remote village in Rayagada.

But NSS leaders said they had not been able to trace Lado Sikaka till evening.