Malaysia’s ringgit tumbled to the weakest level since 1998, extending an eighth week of declines as falling oil prices and political turmoil spur capital outflows.

The ringgit dropped 1.4 percent to 4.067 per dollar at 9:56 a.m. in Kuala Lumpur, extending this week’s retreat to 3.6 percent. Oil dropped 0.4 percent in New York, heading for the lowest close since 2009.

Foreign funds have dumped about $3 billion of the nation’s shares this year as Prime Minister Najib Razak grapples with allegations of financial irregularities at a state investment company. The export-dependent economy is also threatened by a rout in commodity prices and China’s yuan devaluation this week.

Gross domestic product rose 4.9 percent in the three months through June from a year earlier, after climbing 5.6 percent in the previous quarter, the central bank said in Kuala Lumpur Thursday.