Turkey's government said it was fending off a "mini coup attempt" by elements in the police and judiciary who served the interests of foreign and domestic forces bent on humbling the country.

Deputy Prime Minister Ali Babacan said the ruling AK Party had in the past survived military coup plots and attempts in the courts to outlaw it. It would not now yield to a corruption investigation he said targeted the government but was already damaging the national economy.

"These latest formations in the judiciary and the police, we can't call it a coup, but a mini coup attempt. This is what interests foreign investors," he said, echoing suggestions by Prime Minister Tayyip Erdogan of a foreign interest in the crisis.

"Maybe the clearest indicator of this was the fall in share prices," added Mr Babacan, who is in charge of the economy.

The market value of Turkish listed companies had fallen $49 billion by Monday's market close, he said.

Mr Erdogan has, without naming it, accused a movement led by Turkish cleric Fethullah Gulen of creating a "state within a state", using influence in the police and judiciary in a campaign to discredit the government.

The "Hizmet" (Service) movement controls a vast global network of schools and businesses. Tensions have grown between the two former allies over elements of foreign and domestic policy and moves to close his private schools in Turkey.