Footage released by Reuters said they tracked three North Korean armored vehicles and self-propelled artillery near the border with South Korea, as tensions between the two countries escalated over the detonation of land mines in the demilitarized zone. According to the agency, about 20 to 30 North Korean soldiers were seen working on building a fence inside the border area, while Pyongyang and Seoul traded blame for the incident, amid the North's warnings against taking defensive measures and South Korea's calls for dialogue to contain tensions.