(Reuters) - The U.S. Army Corps of Engineers closed a Mississippi River lock on Friday morning due to high water and is likely to shutter another over the weekend, halting grain barge movement on the key shipping waterway as the Midwest harvest is gaining pace.

Lock 17 near New Boston, Illinois, was closed on Friday and is expected to remain down through next Wednesday, according to the latest National Weather Service river forecast. Lock 18 near Gladstone, Illinois, is expected to close for one to two days later this weekend, the forecast showed.

(Reporting by Karl Plume in Chicago; Editing by Chizu Nomiyama)