Asian stocks got off to a shaky start on Monday after a renewed FBI probe of U.S. Democratic presidential candidate Hillary Clinton's use of a personal email server sparked fresh tumult in markets, just days before the Nov. 8 presidential vote.

People are reflected in a display showing market indices outside a brokerage in Tokyo, Japan, February 10, 2016.

The Japanese yen, seen as a safe-haven in times of uncertainty, rose slightly against the U.S. dollar.

MSCI's broadest index of Asia-Pacific shares outside Japan was off 0.2 percent in early trading on Monday. It is set to end the month down 2 percent.

Japan's Nikkei slipped 0.6 percent, but remains poised for a monthly gain of 5.4 percent.

On Friday, Wall Street and the dollar closed lower, after FBI Director James Comey sent a letter to the U.S. Congress informing it that the agency is again reviewing emails related to the private server Clinton used when she was secretary of state.

Markets have tended to see Clinton as the candidate of the status quo, while there is greater uncertainty over what a victory for her Republican rival Donald Trump might mean for U.S. foreign policy, international trade deals or the domestic economy.

Comey had decided in July that the Federal Bureau of Investigation was not going to seek prosecution of Clinton for her handling of classified materials.

"There seems little doubt that a Trump victory would trigger selling in stock markets from current levels," Rick Spooner, chief market analyst at CMC Markets in Sydney, wrote in a note. "This has traders nervous as they start the week assimilating fresh news on Hillary Clinton’s email problems."

U.S. media reported on Sunday that the FBI has secured a warrant to examine newly discovered emails related to Clinton's private server,

Trump had fallen in the polls for most of the past six weeks, but an ABC News/Washington Post poll released on Sunday showed Clinton with a statistically insignificant 1-point national lead on her Republican rival.

The dollar surged 0.7 percent against the Mexican peso on Friday and extended those gains by another 0.2 percent to 18.9982 peso early on Monday.

A Trump victory has been viewed as a key risk for the Mexican currency given his promises to clamp down on immigration and redraw trade relations with the country.

The dollar was little changed at 104.86 yen early on Monday after falling 0.4 percent on Friday. It remains up 3.4 percent for the month.

The euro retreated 0.2 percent to $1.0970 in early trade after jumping 0.9 percent on Friday. It is poised to end October with a 2.5 percent loss.

Adding to the list of potential market-moving events this week is a raft of PMI data out of several countries; central bank policy meetings, including Japan and Australia on Tuesday, the U.S. on Wednesday and the Bank of England on Thursday as well as U.S. October non-farm payrolls on Friday.

Oil prices extended their slide - driven by renewed oversupply concerns - and have surrendered most of the gains made in the first half of October. They are set to end the month with meager gains.

The latest oil woes were prompted after non-OPEC producers failed to make any specific commitment to join the Organization of Petroleum Exporting Countries in limiting output to support prices on Saturday.

U.S. crude slid 0.5 percent to $48.44 a barrel on Monday, up 0.4 percent for the month, while global benchmark Brent retreated 0.5 percent to $49.44, up 0.8 percent in October.

Source: Reuters