A patrol unit from the naval base in Batam foiled attempts to smuggle 5,540 tons of granite and sand to Singapore that could have caused the state to lose a total of around Rp35 billion, ANTARA quoted a navy spokesman as saying. The navy patrol unit seized four boats belonging to Singaporean shipping companies that were carrying the goods on Saturday night and Sunday morning, the chief of the Batam naval base, Col M Faisal, said here on Monday. Two boats were seized in waters north of Tolop Island, namely TBB Keasin and TKB Profit 2101 belonging to Samwoh Exploration Singapore. The boats flying the Mongolian and Singaporean flags carried 2,688 tons of granite from Tanjung Balai Karimun for Pasir Ris, Singapore. None of the boats carried official documents. The other two boats, namely TBB Sea Shore 7 and TKB BHS 236 belonging to Sea Shore Marine Pte Ltd Singapore were seized in waters west of Nipah Island while carrying a total of 2,852 tons of granite from Tanjung Balai Karimun to Pasir Tuas in Singapore on Sunday morning. These boats also did not carry the required documents.