German Economy Minister and Vice Chancellor Sigmar Gabriel hit back at Deutsche Bank Chief Executive John Cryan for telling employees his bank was suffering from market speculation , saying on Sunday that a bank that makes speculation its business should not complain about speculators.

Deutsche Bank was embroiled in a market storm last week over concerns the lender did not have enough funds to cover a reported U.S. Department of Justice (DOJ) demand for $14 billion to settle claims that it had sold toxic mortgage-backed securities before the global financial crisis.

A war of words has escalated surrounding the troubled German lender Deutsche Bank between its supporters and those claiming the bank has no one to blame for its plummeting share price and difficulties but itself.

"I didn't know whether I should laugh or be furious that a bank which turned speculation into a business model now declares itself the victim of speculators," he told reporters on a plane to Iran, which he is visiting with a business delegation, Reuters reported.

In the German media, politicians have accused the U.S. of waging an "economic war" against the lender while several chief executives of DAX-listed companies – including Daimler, TUI, Siemens, Munich Re and Eon, expressing their support for Deutsche Bank.

German media have also focused this weekend on the fact that German Chancellor Angela Merkel cannot afford politically to bail out the bank given her tough stance towards other banking bailouts in other euro zone countries.

Deutsche Bank's luck appeared to turn by Friday, however, as its U.S.-listed shares jumped 14 percent after the AFP news agency, citing a source, reported that the bank could be near a lower, $5.4 billion settlement with the DOJ.

CNBC could not independently confirm the report and hopes of a settlement quickly began to fade, not least because had a new agreement been reached, German law requires banks to formally disclose the details immediately.

This week, markets will be watching for any more news on possible settlement talks. German newspaper Frankfurter Allgemeine Zeitung reported at the weekend that Deutsche's CEO John Cryan would be in Washington this week for annual IMF and World Bank meetings, and other senior Deutsche Bank executives would join him to negotiate a settlement with U.S. authorities.

There is a widespread belief that the bank wants to get a deal done before the administration changes after the November 8 election.

In another separate blow for the bank, 13 past and present executives from Deutsche Bank, Banca Monte dei Paschi di Siena and Nomura have been ordered to stand trial for a number of alleged financial crimes relating to complex derivatives transactions. All those indicted have previously denied any wrongdoing, Reuters reported.

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