The volume of inter-Korean maritime transportation reached a record high in 2006 despite increased tension caused by the nuclear issues on the Korean Peninsula, the South Korean Ministry of Maritime Affairs and Fisheries said Wednesday.

According to the ministry, South Korea shipped 5,469 TEUs of goods to the Democratic People's Republic of Korea (DPRK) via two inter-Korean regular sea routes, while 6,860 TEUs of goods were transported to South Korea from the DPRK.

Meanwhile, the volume of inter-Korean maritime transportation via irregular sea routes was recorded at 15.7 million tons last year, up 6.5 million tons from the previous year, the ministry said.

The expansion of the transportation is mainly backed on a sharp rise in sand exports from the DPRK, the ministry said. South Korean companies imported sand from the DPRK due to South Korea's increased environmental regulation.

Most of the items shipped to the South from the DPRK were assembled goods, raw materials and fisheries products, while Seoul sent mainly relief goods to DPRK, the ministry said.

TEU stands for a 20-foot-equivalent unit.