Mineral products accounted for 23% of Lithuania's exports in 2001, and the production of amber was an important industry. Cement, clays, dolomite, limestone, nitrogen, glass sand, and sand and gravel were the primary mineral products of Lithuania, whose industrial minerals assured self-sufficiency in construction materials. Lithuania remained dependent on imports for its metals and fuel needs. Peat was extracted in the Siauliai, Ezherelis, Paraistis, and Baltoyi-Boke regions. Mineral production figures in 2000 included: limestone, 783,300 tons, down from 1.08 million tons in 1999 and 4 million tons in 1994; and cement, 569,500 tons, compared to 788,300 in 1998 and 150,000 in 1994. Following complaints from Lithuania's sole producers of cement and quicklime, the government launched antidumping investigations directed against Belarussian products. If the government were to take steps to protect the domestic construction material market, Lithuania could lose its export market in Belarus.