On Monday, Chinese forces took control of U.S.-allied vessels in a highly intense escalation in the South China Sea. The incident, captured in chaotic footage released on Wednesday and Thursday, shows the Chinese Coast Guard engaging with Philippine navy boats that were en route to deliver supplies to an outpost in the region. The footage reveals Chinese Coast Guard vessels forcefully colliding with one of the boats and boarding the second one. They proceeded to damage and confiscate equipment, harm crew members, and brandish knives, spears, and axes.

“We were outnumbered and their weapons were unexpected but our personnel fought with everything that they had,” General Romeo Brawner Jr, chief of staff of the Armed Forces of the Philippines, said in a statement on Thursday. “Only pirates do this. Only pirates board, steal, and destroy ships, equipment, and belongings.”

The AP reported that the incident took place at the Second Thomas Shoal, a contentious area in the South China Sea where tensions between the Philippines and China run high. Two Filipino boats were approached by the Chinese Coast Guard as they were trying to replenish supplies at a military base on the reef.

According to the Council on Foreign Relations, China asserts that the South China Sea belongs exclusively to them, despite the fact that this claim is challenged by most of the global community. While conflicts between the Philippines and China in the region are not uncommon, the recent events on Monday represent a significant escalation in hostilities over the territorial dispute. The Wall Street Journal noted that this is the first time Chinese forces have used bladed weapons against Filipino forces.