Shortly before midnight on the night of 12 August, the PVA probed the division's sector at three points. While one PVA patrol was stumbling into an ambush set by Korean Marines, another harried a Marine outpost east of Bunker Hill. The third and strongest blow, however, landed after midnight at Stromboli, a Marine outpost on Hill 48A northeast of Bunker Hill at the far right of the sector held by the 1st Marine Regiment, near the boundary with the 5th Marine Regiment. In conjunction with the attack on Stromboli, launched in the early hours of August 13, the PVA hit Company F on the right of the line held by the 1st Marines. The PVA failed to crack the Jamestown defenses, but they inflicted so many casualties at Stromboli that reinforcements had to be sent. The reinforcing unit, a squad from Company F, came under mortar and machine gun fire from the PVA probing Company F's defenses and had to return to the MLR. Pressure against Stromboli and its defenders continued until the commander of Company F sent a stronger force that fought its way to the outpost, breaking the PVA encirclement. The 5th Marines moved one company into a blocking position behind the Jamestown Line near Stromboli in case the fighting again flared at that outpost. Meanwhile, the PVA attempted to seize Bunker Hill. At about 01:00 on 13 August, intense PVA artillery and mortar fire persuaded Captain Connolly of Company I to request box-me-in fires, which the 11th Marine Regiment provided immediately. PVA infantry, supported by machine gun fire, advanced behind bursting shells, but the Marines fought back with every weapon they could bring to bear - artillery, mortars, tank guns, rockets, rifles, and automatic weapons. After almost four hours, the violence abated as the PVA relaxed his pressure on Bunker Hill. Company G, 3/7 Marines, joined 3/1 Marines before the PVA broke off the action and withdrew behind a screen of artillery and mortar fire. Except for a determined few, whom the Marines killed, the PVA abandoned Bunker Hill. Colonel Layer took advantage of the lull to send Company H, 3/7 Marines, to relieve the Marines holding the hill. He afterward withdrew all the other elements of the 7th Marines that had reinforced his regiment, but not until a patrol from Company I had reconnoitered the far slope of the hill. In keeping with their usual tactics, the PVA tried to divert attention from Bunker Hill before attacking again.