Oil prices fell on Friday as a strong dollar, mixed economic signals and concern over China's economy weighed on investor sentiment.

Brent crude prices fell by 41 cents, or 0.5%, to $84.70 a barrel by 0650 GMT. U.S. West Texas Intermediate crude futures fell 49 cents, or 0.6%, to $82.33 a barrel.  

For the week, Brent was down 0.3%, while WTI was trading marginally higher.  

The U.S. dollar index climbed for the second consecutive session after stronger-than-expected data on the U.S. labour market and manufacturing earlier in the week. A stronger greenback dampens demand for dollar-denominated oil from buyers holding other currencies.  

A lack of concrete stimulus measures from top oil importer China has also weighed on commodities overall, ANZ analysts said in a note. China's economy grew at a slower-than-expected 4.7% pace in the second quarter, official data showed, sparking concerns about the country's oil demand.  

"Concerns over supply in the short term kept the losses minimal," ANZ said, however, referring to worsening wildfires threatening production in Canadian oil sands.

Elsewhere on the economic front, Japan's core inflation perked up in June, leaving the door open for an interest rate hike in the major oil market.

Oil prices found some support in the prior two sessions after the U.S. government reported a bigger-than-expected weekly decline in oil stockpiles.

Analysts at consultancy firm FGE, though, said broader inventory trends look more bearish than expected this month. They noted U.S. crude stocks have drawn at a slower-than-usual pace for this time of the year and global fuel stocks rose last week.

Meanwhile, the OPEC+ producer group is unlikely to recommend changing the group's output policy, including a plan to start unwinding one layer of oil output cuts from October, three sources told Reuters on Thursday.