Marines of South Korea and the US are holding an annual joint exercise in the southeastern part of South Korea this week to bolster their defense posture against terrorism, the South Korean Marine Corps said Wednesday. According to the South Korean Marines, some 100 South Korean troops and about 50 US Marines started the joint exercise on Monday at the 1st Marine Division in Pohang, about 370 kilometers southeast of Seoul. The exercise will wrap up next Thursday, according to South Korea''s news agency (Yonhap). The Marines said the exercise will include shooting drills, close quarters battle training and guerrilla training. The two Marine forces have been holding regular joint drills in South Korea since 1976. "Through the exercise, we seek to exchange and share combat techniques with each other and strengthen our ties," the South Korean Marine Corps said in a statement. "We expect this occasion to help us optimize our joint combat capabilities."