European shares fell 3 percent today after trading was suspended on the Chinese markets earlier for the second time this week. Shares in China fell by 7 percent, triggering a circuit-breaker rule which is designed to stop panic selling, which came in the first 30 minutes of trading, making it China's shortest trading day on record. The slump prompted renewed panic on global markets. Amid the uncertainty, the euro gained more than half a cent against the dollar. The pound fell against the euro by 1.23 percent.Investors are nervous after the Chinese central bank moved to weaken the country's currency, the yuan, for the eighth day running, sparking fears of a currency war. The move is designed to boost exports by making Chinese goods cheaper outside the country, analysts have speculated. It is also being interpreted as an indication that consumer demand in China may be slowing more sharply than feared.