United Nations X Corps 42nd Army ：32 killed100 wounded[3] The Battle of the Twin Tunnels (French: Bataille de Twin-Tunnels) took place during the Korean War.

[4] In the recent course of protecting IX Corps' right, a joint motorized patrol from the 2nd and 24th Infantry Divisions on 29 January had moved north out of the Yoju area on the east side of the Han River to a pair of railroad tunnels and a connecting bridge standing east and west athwart a narrow valley 4 miles (6.4 km) south of Chip’yong-ni.

The PVA finally backed away after air strikes were called in by the pilot of an observation plane who spotted the ambush and after a motorized company of infantry reinforced the group about 03:30 on the 30th.

In hard, close-in fighting lasting all day, the defending battalions, relying heavily on artillery fire and on more than 80 air strikes finally forced the PVA to withdraw.

Eighth Army possession of Chip’yong-ni, furthermore, would pose a threat of envelopment to enemy forces opposing I and IX Corps below the Han River.

This force, apparently part of the KPA V Corps, could be preparing to advance southwest on Route 24 through Chip’yongni, then down the Han valley toward Yoju and Ch’ungju.