Six South Korean college students who were taken into police custody after staging a protest performance over Japan's export restrictions inside the Japanese Consulate in Busan were all released later that day after eight hours of questioning, according to the Busan Dongbu Police Station on Tuesday.

The students, who belong to an activist group named the Busan Youth and Student Action Group, were detained at 2:35 p.m. on Monday for trespassing on the consulate premises and underwent questioning for eight hours before being set free at 10:20 p.m.

The students admitted to some of their offenses, the police said.

The students are accused of displaying placards condemning Japan's export curbs for South Korea and shouting slogans, such as "Abe must apologize," on the consulate's yard after dashing out of its library. They had earlier entered the Japanese mission Monday morning through due procedures for use of its library.

"Students acknowledged parts of their wrongdoings. They were booked on charges of trespassing and will be additionally grilled before being prosecuted or not," a police investigator said.

Police also booked one Busan civic activist accused of hindering the police crackdown on the student protesters and damaging police vehicles.

At the time of the protest performances, a coalition of 30 civic groups in the southern port city was holding a joint news conference in front of the consulate's rear gate to condemn Japan for its export restrictions against South Korea and call for a boycott of Japanese products.

Following the surprise protest, the consulate reportedly sent emergency emails to Japanese nationals living in Busan, asking them to stay alert for protesters and tighten security for Japan-related facilities in the city.

Japan began applying the export curbs on South Korea for three key materials needed for the production of chips and displays on July 4 in apparent response to Seoul's handling of a wartime forced labor issue. Tokyo is pushing to remove South Korea from a list of trusted buyers, which could negatively affect the supply of other key materials needed for making smartphones, televisions and other industrial materials. (Yonhap)