South Korea and the United States kicked off a joint underwater excavation project Tuesday in waters off the southeastern port city of Busan to search for the remains of American soldiers killed during the 1950-53 Korean War, the defense ministry said. Some 22 personnel from the ministry's Agency for KIA Recovery and Identification and the U.S. Defense POW/MIA Accounting Agency (DPAA) were deployed in the search, spanning an area of around 12 square kilometers, which will run through Sept. 27, according to the ministry. KIA stands for killed in action, while POW and MIA are acronyms for prisoners of war and missing in action, respectively. Three American service members are presumed to have been killed in January 1953, when a U.S. B-26 bomber crashed into the sea shortly after takeoff from the K-9 air base in the port city, 325 kilometers southeast of Seoul. The two sides have regularly conducted joint searches for the remains of missing Americans after signing an agreement for joint war remains excava tions in 2011. More than 1.7 million U.S. troops served in the Korean theater of operations during the Korean War, with more than 36,000 killed, according to data from the U.N. Command. Nearly 7,500 Americans still remain unaccounted for from the three-year conflict, according to DAPA. Source: Yonhap News Agency