Oil prices tumbled more than 5 per cent in volatile trading on Tuesday as planned production curbs by global producers, led by Saudi Arabia and Russia, failed to allay concerns about oversupply stoked by swelling US shale output. Fears about weaker oil demand amid a potential slowdown in the global economy have also added to worries about how effective the supply cuts agreed earlier this month will be. The fall in oil comes amid broader pressure on global equities markets due to persistent worries over how the US-China trade war could hit economic growth. Brent crude, the international benchmark, declined 5.6 per cent to settle at $56.26 a barrel in its third straight day of declines. Financial Times