Tensions along the border between South Korea and the Democratic People's Republic of Korea (DPRK) have heightened as South Korea resumed propaganda broadcasts through loudspeakers in response to Pyongyang's retaliatory sending of garbage balloons into the South.

South Korea's joint chiefs of staff confirmed that the loudspeaker broadcasts resumed on Sunday afternoon, marking the first time such broadcasts have occurred since January 2016 when they were used in response to the DPRK's fourth nuclear test, South Korean news agency Yonhap reports.

The decision to resume the broadcasts came after South Korea's National Security Council (NSC) approved the measure at an emergency meeting on Sunday.

Meanwhile, Deputy Department Director of the Publicity and Information Department Kim Yo Jong warned that if South Korea continues with its leaflet-scattering and loudspeaker provocations, they will face a new response from the DPRK.

Kim also revealed that the DPRK had sent 7.5 tons of non-propaganda paper in 1,400 balloons to South Korea on June 8 and 9, intending to cease the activity the same day, but the situation changed.

In response to DPRK's recent actions, the South Korean military announced on Tuesday its decision to resume all military activities in the demilitarized zone and islands near the DPRK, previously restricted by the inter-Korean military agreement. South Korea attributed the escalation to DPRK.

Read more: South Korea approves suspension of inter-Korean military agreement

On Saturday, the DPRK deployed hundreds of balloons carrying bags of trash into South Korea, citing them as retaliation for anti-Pyongyang propaganda balloons launched by South Korean activists.

Despite Pyongyang's announcement of a cessation of the balloon launches last Sunday, South Korean activist groups continued their activities.

The "Fighters for Free North Korea" group claimed to have sent balloons containing USB thumb drives loaded with K-pop music and 200,000 leaflets criticizing Kim Jong Un. Another group of alleged North Korean defectors dispatched balloons containing anti-Pyongyang leaflets, radios, and USB thumb drives featuring a speech by South Korean President Yoon Suk Yeol.

The DPRK had previously warned of further retaliation, promising to send "wastepaper and rubbish" in quantity one hundred times greater if South Korean leaflets continued to be dispatched.

In 2020, South Korea's Constitutional Court invalidated a law criminalizing the sending of anti-Pyongyang propaganda, citing it as an undue restriction on free speech. Consequently, experts argue that there are currently no legal grounds for the government to intervene in activists' balloon launches into the DPRK. The South Korean Unification Ministry stated that the issue is being deliberated in light of the 2023 court ruling.

Kim Yo Jong derided South Korea's objections to the balloons, asserting that DPRK citizens were exercising their freedom of expression.