HOUSTON, July 17 (Xinhua) -- The American Petroleum Institute (API) on Tuesday reported an increase of about 0.63 million barrels in the U.S. crude oil inventories for the week ending July 13.

In the previous week, API reported draws of nearly 6.8 million barrels in the U.S. crude oil inventories for the week ending July 6.

Oil prices went up slightly on Tuesday after slumping over 4 percent in the previous session.

The West Texas Intermediate (WTI) for August delivery added two U.S. cents to settle at 68.08 dollars a barrel on the New York Mercantile Exchange, while Brent crude for September delivery increased 0.32 dollar to close at 72.16 dollars a barrel on the London ICE Futures Exchange.