London, March 14 : Global financial markets have come under severe pressure after the collapse of Silicon Valley Bank, despite governments on both sides of the Atlantic taking extraordinary measures to maintain confidence in the banking system, The Guardian reported. However, shares in the US and European banks sold off sharply amid a crisis of confidence in global markets over the health of the financial system. Government bond prices soared as investors rushed for safe-haven assets, while economists suggested the febrile conditions in global markets could force the world's most powerful central banks to stop raising interest rates. Shares in regional American lenders were thrown into a tailspin, led by a more than 60 per cent collapse in the value of California-based First Republic Bank, and similar double-digit declines for lenders, including Western Alliance Bancorp and PacWest Bancorp amid frenzied speculation over contagion risks, The Guardian reported. Ratings agency Moody's on Monday downgraded the debt ratings of the collapsed Signature Bank deep into junk territory and placed the ratings of six other US banks under review for a downgrade. The banks placed under review for downgrade were First Republic Bank, Zions Bancorporation, Western Alliance Bancorp, Comerica Inc, UMB Financial Corp and Intrust Financial Corporation, The Guardian reported. Moody's, which rated Signature Bank's subordinate debt "C", said it was also withdrawing future ratings for the collapsed bank. The KBW banks index, which includes the biggest American banks, fell by more than 10 per cent, even as the US benchmark S&P 500 index and Dow Jones industrial average rose by about 0.5 per cent, The Guardian reported. In London, shares in the UK's biggest banks tumbled, with Barclays and Standard Chartered dropping by more than 6 per cent. Markets across Europe sold off sharply, as the FTSE 100 tumbled by 2.5 per cent in the biggest one-day fall since last summer, The Guardian reported. Shares in banks around the world slumped despite reassurances from the US president that America's financial system is safe, BBC reported. It comes after authorities had to step in to protect customer deposits when the US lenders Silicon Valley Bank (SVB) and Signature Bank collapsed. Earlier on Monday, Spain's Santander and Germany's Commerzbank saw their share prices dive by more than 10 per cent at one point, BBC reported. A string of smaller US banks suffered even worse losses than European counterparts on Monday, despite reassuring customers that they had more than enough liquidity to protect themselves from shocks. The volatility has led to speculation that America's Federal Reserve will now pause its plans to keep raising interest rates, designed to tame inflation, BBC reported. /IANS