Asian shares slipped from near three-week highs on Friday as a rally in oil prices reversed and investors remained wary about the outlook for the global economy.

MSCI’s broadest index of Asia-Pacific shares outside Japan fell 0.7 percent, but gains in previous sessions left it up 4 percent for the week while Japan’s Nikkei shed 2.2 percent as the yen strengthened but remained on track for a weekly gain of 5.9 percent. A stronger yen is a damaging for exporters as it reduces their overseas profits when converted into local currency.

According to Evan Lucas, market strategist at trading services provider IG, “This week is the first sign of change I have seen in 2016.”

The Korean Kospi was flat while Hong Kong’s Hang Seng index slipped 0.55 percent. Chinese markets began the day lower with the Shanghai composite lower 0.47 percent while the Shenzhen composite was flat.

Down Under, the S&P/ASX 200 was down 0.92 percent, dragged by the energy and financials sectors, both down 3.24 and 0.26 percent, respectively.

Oil Prices Reversed Gains

Oil prices reversed earlier gains on Thursday following a rise in U.S. stockpiles but may post their first rise in three weeks after the battered market was bolstered by the announcement of a tentative deal by major producers to freeze output at January’s highs.

Brent crude extended losses on Friday, trading down 0.8 percent at $34.02 per barrel, but remaining up 2 percent for the week. U.S. crude last traded at $30.56, off a two-week high of $31.98 hit on Thursday but up 3.8 percent so far this week.