Detachment 202 trained the guerrillas who killed 2,000 Japanese at Kaifeng

By Harlan Pryce · August 17, 2026

OSS agents in Kunming trained Chinese commandos in mortars and bazookas before the 1945 Yellow River bridge bombing, details preserved in a photograph series by a man named Garvin.

Between 1,200 and 2,000 Japanese soldiers were killed in a single blast when a train struck mines on the Yellow River Railway Bridge in August 1945. The explosion, orchestrated by the Office of Strategic Services and Chinese guerrillas, erased a double-track bridge and every man on that train.

This was the operational fruit of Detachment 202. Based in Kunming, China, the detachment served as the primary hub for OSS operations in the China Theater starting in 1944. The work of such a unit is rarely captured in the moment of the strike—the mines are set in silence, the train arrives in the dark—but the preparation is a matter of record.

A series of photographs from the US National Archives, captured by a man named Garvin, provides a glimpse into the pipeline that led to the Kaifeng disaster. The file's catalogue entry records a visual history of the Kunming field station, focusing heavily on the intersection of American expertise and Chinese manpower.

Unit 25 Commando School

Training an asset is a slow process of subtraction: you strip away the civilian habits and replace them with the mechanical requirements of the trade. In May 1945, the OSS operated the Unit 25 Chinese Commando School. According to the archival description, the photographs from this period show American officers training Chinese troops in the use of the rifle, the mortar, the bazooka, and the Bren gun.

These were not ceremonial weapons. The Bren gun provided the sustained fire necessary for an ambush, while the mortar and bazooka allowed a small team to punch above its weight against armored targets or fortified positions. The catalogue entry specifically mentions images of "sighting and target practice," the repetitive, grueling work that ensures a man does not miss when he only has one chance to blow a bridge.

When you look at the timeline, the proximity of this training to the August attack on the Yellow River bridge is telling. The commandos were being polished in May; by August, they were effectively erasing a Japanese regiment from the map.

Bazookas and Basketball

Tradecraft is as much about the mind and body as it is about the weapon. The records of the Kunming station suggest a holistic approach to building a fighting force. The photographs do not only show the violence of the bazooka; they record Chinese troops in formation, marching, and performing calisthenics.

There are even images of the troops playing basketball and undergoing medical inspections. To the casual observer, basketball seems a triviality in a war zone. To the operator, it is a tool for cohesion and physical conditioning. A man who can move laterally on a court and maintain his wind can move through the brush of the China Theater. The medical inspections ensure the asset is a viable tool, not a liability who will collapse from malaria or dysentery before the objective is reached.

This disciplined regimen culminated in the "awards ceremony" noted in the archive. Recognition is a powerful motivator for irregular forces. When an American officer pins a medal on a guerrilla, he is not just rewarding past performance; he is securing future loyalty.

Unit 16

The archival record is not complete. While it documents the training of the commandos and the daily life of the station, it leaves significant gaps regarding the physical footprint of the OSS in Kunming. The catalogue entry mentions photographs of "unidentified buildings," which were originally marked only as "Unit 16, China."

These buildings may have served as the headquarters for the Kunming command, but the archive does not explicitly confirm their purpose. They remain anonymous structures in a city that was once the nerve center for some of the most daring sabotage missions of the Pacific War.

Related files, such as the Overseas Cable Files or the photographs of the Kunming Field Station (NAID 540059), hint at a much larger apparatus of coordination. Yet, in this specific series, the identities of many are lost. We have the results of the training at Kaifeng, and we have the image of the training itself, but the man behind the lens—Garvin—remains a name without a biography.

The records leave us wondering what happened to the men of Unit 25 after the bridge fell, and exactly what occurred behind the walls of Unit 16.