Three persons were arrested with a huge quantity of explosives and ammunition in West Bengal's North 24 Parganas district, police said on Thursday.
Acting on a tip-off, the Special Task Force (STF) of the West Bengal Police made the arrests on Wednesday from Shasan, around 30 km from Kolkata, they said.
Ten kg explosives, 20 rounds of ammunition and Rs 40,000 in cash were seized, a senior police officer said.
"We are grilling them to find out their plan and for whom they were working. We are also trying to ascertain whether they have links to any interstate or international terror groups," the officer said.
The investigators are also trying to find whether they are connected to the JMB terrorists arrested in Kolkata on Sunday, he added.