Police raided the homes and offices of nine activists Monday on suspicion of promoting North Korean ideologies in breach of a national security law.

More than 100 investigators collected evidence at the five locations affiliated with the members of Corean Alliance, a civic group based in western Seoul, the Seoul Metropolitan Police Agency (SMPA) said.

The suspects allegedly made online posts endorsing the North's military-first ideology and held protests calling for the abolishment of the South's National Security Law, which bans people from publicly supporting Pyongyang.

Police said the nine secretly sent the co-chairwoman of the group to the North so she could offer condolences over the death of late North Korean leader Kim Jong-il in December 2011.

Investigators also raided the homes and offices of a pastor based in Gimpo, just west of Seoul, who is suspected of authoring and spreading leaflets praising the North, the SMPA said.

Police said they believe Lee attended a seminar hosted by a pro-North Korean group in Germany last year and had contact with the deputy head of a North Korean research institute, identified only by his surname Park.

Lee also allegedly spread leaflets at the seminar claiming that the lighting of a Christmas tree tower near the inter-Korean border in the South was "psychological warfare," police added.

The police move comes after the Constitutional Court on Friday ordered the dissolution of the Unified Progressive Party (UPP), a left-leaning minor opposition party, saying its principles and activities were in violation of the "basic democratic order" stipulated by the nation's Constitution. (Yonhap)