Four ruling Uri Party lawmakers have returned to Seoul after a five-day trip to Pyongyang.

Led by the chairman of the National Assembly's Unification, Foreign Affairs and Trade Committee Lim Chae-jung, the delegation met with the head of North Korea's parliament Kim Yong-nam and Asia-Pacific Peace Committee Chairman Ri Jong-hyok.

The visit was aimed at promoting academic exchanges between the North's National Unification Research Center and Uri's Open Policy Institute.

No details of the talks have been disclosed, but they could have discussed former South Korean President Kim Dae-jung's planned visit to the North.

At the end of last month, Lim met with the ex-president before leaving for the North, prompting speculation that Lim could have conveyed Kim's wish to visit Pyongyang.

Early this month, the former president said he hopes to visit the North in April via a cross-border railway yet to open, following his historic 2000 summit with North Korean leader Kim Jong-il.