The Turkish central bank ramped up its monetary conditions on Monday to shore up the local currency, the lira, after it slumped to a record low value against the dollar.
The bank announced that it was applying immediately a "strong" tightening of monetary conditions.
"A strong extra monetary tightening will start as of today," the bank's governor Erdem Basci said in a statement.
"It's essential that the extra monetary tightening is strong, effective and temporary," he said.
In late morning trading the lira was being traded at 1.9488 to the dollar, having firmed from a record weak level of 1.9740 earlier in the day.
Analysts said the latest decision was not a surprise.
"This is not the first time that the central bank has done this as we have seen two recent episodes of additional tightening on June 11 and between June 19-21 more recently," Sengul Dagdeviren at ING Bank based in Turkey told AFP.
"The move was not a surprise and shows that the central bank will continue to tame volatility within existing policy framework, ready to sell more FX (foreign exchange) via auctions too," she commented.
Basci added that the latest measures would be applied for as long as required, depending on developments on the foreign exchange market.
In a presentation to economists on changes in policy, the bank said that it would continue gradually to shift the way in which the flow of lira was made available to the Turkish financial sector.
This would be done by switching liquidity from net foreign assets to net domestic assets until the bank's next monetary policy committee meeting later this month.
"This strategy will not only soften extremely rapid credit growth but also support the value of the Turkish lira," a summary on the bank's website said.
The central bank is independent of the government in setting monetary policy.
On the government debt market, Turkey's 10-year borrowing rate stood at 8.8 percent as the central bank announced its new tough action.
The yield had climbed to more than 9.0 percent on June 21, amid a wave of unprecedented protests against Prime Minister Recep Tayyip Erdogan and his Islamic-based government.
The borrowing rate was slightly above 6.0 percent in April.
The Istanbul stock market plunged in early June.
Victor in three elections in a row, Erdogan has overseen strong economic growth -- an average five percent a year since he first won office in 2002.
The economy is ranked as the 17th biggest in the world, and the government hopes it will become the 10th-biggest within a decade.
But last month, the governing Justice and Development Party (AKP) was shaken by nationwide demonstrations, the most serious public challenge since it came to power in 2011.
-- 'Interest rate lobby' blamed --
Erdogan blamed various groups both inside and outside the country, including what he called an "interest rate lobby" of speculators pushing for high returns.
This referred to pressure in some quarters for a rise in interest rates to support the currency and retain foreign capital.
Turkey, in common with many emerging economies is subject to signals from the US Federal Reserve bank that it will soon begin to wind down its special injections of money into the financial system to support the US economy.
The prospect that US monetary conditions will become tighter has caused some funds to be withdrawn from emerging economies.
"The pressure on the Turkish lira is solely in parallel to the economic monetary pressure in the rest of the world," said Dagdeviren.
"We don't think local issues have been a significant decoupling factor so far for local markets," she added.
The Turkish economy grew by 2.2 percent in 2012, short of the government forecast of 3.2 percent expansion.
This was a major slowdown from 2010 and 2011 when the Turkish economy grew by 8.9 percent and 8.8 percent respectively.