In mid-October the Vietnamese Marine commanders formed a provisional regiment for Operation PHI-HOA 5, which was to be conducted in III Corps Tactical Zone.[8-D] The 1st, 3d, and 4th Battalions, supported by a composite artillery battery and the reconnaissance company, joined ARVN, VNAF, and Vietnamese Navy units in a major search and clear campaign in the northwest corner of Gia Dinh Province, only about 20 miles southeast of Saigon. Like many other large government military operations undertaken in 1963, this one failed to uncover any major enemy forces. The Communist soldiers again managed to elude government forces. An extensive tunnel and cave network, which the Marines systematically destroyed with demolitions, was discovered under the entire area. Still, the Marines managed to kill only six Viet Cong and capture 10. Two Vietnamese Marines were killed and 36 others wounded before the operation terminated on 1 November. [8-D] After the realignment of the CTZs the previous December, III Corps included a 200-mile-long section of Vietnam which encompassed the southern one third of the Central Highlands and the area south to the boundary of the Capital Military District near Saigon. [Illustration: _General Wallace M. Greene, Jr., Commandant of the Marine Corps, and Lieutenant Colonel Wesley G. Noren, Senior Marine Advisor to the Vietnamese Marine Corps, confer with Lieutenant Colonel Nguyen Ba Lien, Commandant of the Vietnamese Marine Corps. (USMC Photo A420917)._] The coup d’etat which toppled President Diem from power began the same day that Operation PHI-HOA 5 concluded. Instead of returning to their base camps, the 1st and 4th Vietnamese Marine Battalions, accompanied by the composite battery, moved into the capital to participate in the power struggle. These units actually launched the coup by seizing key installations in the heart of the city while the 2d VNMC Battalion blocked the highway to Bien Hoa, thus preventing loyalist intervention. Sporadic fighting against troops loyal to Diem continued until the early morning of 2 November when the 4th Battalion finally stormed and captured the presidental palace. Four Vietnamese Marines were killed and 12 wounded during the battles in Saigon. No U.S. Marines were involved in the fighting as Lieutenant Colonel Noren directed his subordinate advisors to remain in their quarters. When the situation stabilized, the advisors rejoined their units and resumed their normal duties. [Illustration: CORPS TACTICAL ZONES 1963–1964 ]