West Texas Intermediate futures for September delivery rebounded to $48.73 (+0.58%), while Brent crude climbed to $55.48 (+0.38%). However analysts say these gains are unlikely to be sustained as glut concerns persist. Weakness of preliminary data on Chinese manufacturing also weighs on oil as it intensifies concerns over demand. This is going to be the fifth straight week of declines for WTI.

Concerns over additional supplies from Iran are also in place. Iran has large oil reserves on land as well as at sea, and Saudi Arabia, OPEC's leading producer, is not going to cut output or exports to help Tehran sell its crude. Therefore, whenever Iranian oil exports begin to grow, they should put further downward pressure on oil prices.

Gold declined to $1,083.50 (-0.97%) after Markit economics said in its preliminary report that China's Manufacturing PMI contracted once again to 48.2 in July from 49.4 reported previously. This decline spurred demand concerns, which added to expectations of a rate hike by the Federal Reserve and muted inflation worries.

Citibank analyst David Wilson believes that bullion is likely remain under pressure up to the Federal Reserve's September policy meeting. "The markets are all focusing on a September rate hike, so assuming that is when it occurs, you have to think that gold is going to remain under downward pressure up until that point," he said.