Development workers in the Indian state of Manipur say they cannot pay a ransom for a German national kidnapped by separatist rebels.
Manipur police officials say they have launched a massive manhunt for rebels of the Kuki Liberation Army (KLA) who kidnapped Heinrich Wolfgang Grey on Sunday.
Mr Grey was travelling to inspect German-funded development work carried out by the United NGO Mission of Manipur when he was abducted.
Mr Grey is employed by the German-based Church Development Service (EED).
The United NGO Mission of Manipur says it is not in a position to pay the 10 million rupees ($210,000) the KLA wants.
Officials in the German consulate in Calcutta told the BBC that only Mr Grey's family members or employers could negotiate his release.
The consulate has informed Mr Grey's family in Bonn and some relatives may arrive in India soon.
Indian troops face more than a dozen rebel groups in Manipur
Reports say Mr Grey was travelling with a German woman, identified as Edda Kirlies, and officials of local aid groups.
Gunmen stopped their vehicle near the Maphou dam, taking away Mr Grey but leaving the others unharmed.
Police said the Kuki rebels took Mr Grey to a hideout in the state's heavily wooded mountains.
Police and paramilitaries are taking part in the search for the aid worker.
Mr Grey arrived in the state capital, Imphal, on 21 March with Ms Kirlies to inspect the activities of non-governmental organisations funded by Germany.
This is the second time in the last two years that the rebels have kidnapped a foreign national.
Two years ago, two Japanese agricultural experts were kidnapped but later released.
However, the action led to the Japanese pulling out from all projects in the region.
The Kukis have been fighting for more political autonomy in Manipur for more than 30 years.
More than a dozen rebel groups are active in the state.
Rebels accuse the government of neglecting the local economy and welfare of the people.
The Press Trust of India said several women's organisations in Thoubal district held a large rally on Tuesday demanding that the militants free Mr Grey and not kidnap other development workers.