The inter-Korean trade has seen a significant decline of more than 30 percent since the South Korean government carried out a ban on trade with the Democratic People's Republic of Korea (DPRK) for the deadly sinking of its warship Cheonan, Seoul's customs office said Friday.

The Korea Customs Service said that the volume of inter-Korean trade amounted to 123 million U.S. dollars in June, down 32 percent from April.

Outbound shipments from South Korea dropped 27 percent in June compared with April, to register 56.88 million dollars, while inbound shipments from the DPRK shrank 36.5 percent to 66.18 million dollars over the same period.

The South Korean government has severed all trade and cultural ties with the DPRK after a multinational investigation concluded that the South Korean warship sank due to a torpedo attack from the DPRK. Pyongyang has repeately denied the charges.

But an official at the customs agency said the decline was not as sharp as expected, as the Kaesong joint industrial complex, which accounts for near 70 percent of total trade between the two countries, is still in operation.

He said if the situation at the Kaesong complex remains the same down the road, the inter-Korean trade is expected to remain at similar levels to that of June.