PYONGYANG, April 10 (Xinhua) -- The official media of the Democratic People's Republic of Korea (DPRK) on Tuesday called on South Korea to re-investigate the sinking of South Korean corvette Cheonan in March 2010, calling the issue a stumbling block to improving north-south relations.

The official Korean Central News Agency (KCNA) said in an article that there is increasing voice for re-investigation into the case of Cheonan in South Korea, as some 70 percent of South Koreans don't believe the result of investigation.

Forty-six South Korean sailors were killed when Cheonan was sunken eight years ago. South Korea said a DPRK torpedo attacked the corvette, which was repeatedly denied by Pyongyang.

"The demand for re-investigation into the case getting stronger amid mounting atmosphere of national reconciliation and unity proves that the case is one of the biggest stumbling blocks in the way of improving the north-south ties," said the KCNA.

The DPRK and South Korea have been improving relations since the beginning of the year and the leaders of the two sides are scheduled to hold a summit meeting on April 27, which will be the first in over 10 years.