The Turkish lira plunged to an all-time low, stocks crashed prompting a trading halt, and government bond yields surged to their highest levels this year as investors dumped the country’s assets following the arrest of President Recep Tayyip Erdogan’s key political rival, sharply raising political risks, Bloomberg reports.

The Borsa Istanbul 100 index dropped by 6.9% at the opening of trading, triggering a halt in trading. After resuming, the index continued lower, falling 4.6%.

Turkey’s 10-year government bonds slumped, driving yields up by 175 basis points to 29.94%.

The lira tumbled by more than 12% against the U.S. dollar, hitting a record low of 41.10 at one point. By 11:45 Moscow time, the USD/TRY pair was trading nearly 7% higher, slightly below the 40 mark.

Istanbul Mayor Ekrem Imamoglu was detained on Wednesday morning, just one day after Turkish authorities invalidated his university diploma—a move that could prevent him from challenging Erdogan in the next presidential election.

The 54-year-old Imamoglu is widely seen as Erdogan’s main presidential rival. Last year, he defeated an Erdogan-backed candidate in Istanbul’s mayoral elections and was set to be announced on Sunday as the presidential candidate for the main opposition Republican People’s Party (CHP).

“Turkish assets are under significant selling pressure,” said Piotr Matys, senior FX analyst at In Touch Capital Markets. “For some investors, this is also a reminder that President Erdogan is determined to consolidate his power further by sidelining his chief political rival ahead of the presidential elections scheduled for 2028—though early elections cannot be ruled out.”