Police said that the youths were arrested on a tip off near Sunny enclave at Mohali and did not rule out their links with Pakistan terror elements.
They also seized mobile SIM cards, two AK 47 rifles and five pistols from their possession.
Police claimed that the arms and ammunition recovered from them are manufactured in Pakistan, China and Brazil.
Investigation is under progress, police said.
The arrests came as an operation was on to eliminate the terrorists who attacked the Pathankot air base in the state on Saturday.