Three Afghan nationals and a Nigerian, members of an international drug syndicate, were arrested with over 2 kg heroin worth Rs 10 crore, a police officer said on Friday.The accused smuggled the drug into India after swallowing heroin-filled capsules to dodge security at the airport."Ehsanullah (28), Mohammed Amin (47), Abdul Razzak (43) are Afghanistan nationals, while their accomplice, Nnadozie Emmanuel (32) is a Nigerian national. Following a tip-off, a Special Cell team arrested the accused after conducting separate raids on Wednesday and Thursday at their flats located in south Delhi," Deputy Commissioner of Police PS Kushwah said.Emmanuel came to India on a student visa in 2011 and came in contact with fellow Nigerian nationals involved in drug trafficking, Kushwah said."Emmanuel later joined Ehsanullah, Amin, Razzak and some other Afghan nationals. He only dealt in fine quality heroin smuggled into India from Afghanistan. He was staying illegally in India," Kushwah said."They smuggled heroin into India by swallowing its capsules to dodge security at the airport. Each capsule weighs about 20 gm and each carrier would swallow a few dozen capsules at one go," the DCP added."The gang members did not eat or drink anything during the entire operation and excreted the capsules upon reaching India. They were tasked to sell the drugs through designated receivers," he said."Efforts are on to nab the main suppliers and receivers of heroin. The heroin recovered from them costs Rs 10 crore," he added.