South Korea has launched an investigation into Kim Yo-jong, the sister of North Korean leader Kim Jong-un, for last month’s attack on the inter-Korean liaison office, local media reported on Thursday.

The symbolic probe was launched after a South Korean lawyer filed a criminal complaint against Pyongyang last week for the demolition of the office in mid-June, Yonhap News Agency reported.

North Korea’s army chief Gen. Pak Jong-chon has also been named in the investigation along with Kim Yo-jong, who serves as the first vice department director of the ruling Workers’ Party’s Central Committee.

However, prosecutors will review the complaint before deciding whether to apply charges against the North Korean officials.

Pyongyang blew up the inter-Korean liaison office in its Kaesong border district on June 16, just days after Kim Yo-jong warned of such a move, as tensions escalated over propaganda leaflets sent into North Korea from the South.

Seoul has recently moved to defuse tensions, saying last Tuesday that it may ban two North Korean defector groups in the country responsible for sending the leaflets.

The South Korean Unification Ministry filed a criminal complaint against two North Korean groups – Fighters for a Free North Korea and Kuensaem – and revoked their permits.

On Thursday, South Korean President Moon Jae-in asked the country’s lawmakers to “institutionalize the accomplishments of South-North summit talks so far,” Yonhap reported.

Addressing the opening ceremony of South Korea’s 21st National Assembly, he said bipartisan support is needed for progress in the “vulnerable” peace process.

The president expressed hope that inter-Korean parliamentary talks could take place before the four-year term of the new lawmakers ends.

“If the two Koreas cooperate on the basis of trust, it would benefit both of them,” he said, emphasizing the need for dialogue to build trust and achieve lasting peace.