International Monetary Fund has said the global economy has weakened further and warned it is highly vulnerable to adverse shocks. It said the weakening has come amid increasing financial turbulence and falling asset prices. The IMF report comes before the meeting of G20 Finance Ministers and central bank Governors in Shanghai later this week. It said, China's slowdown is adding to global economic growth concerns. China's economy, the second biggest in the world, is growing at the slowest rate in 25 years. The IMF also noted any future prospects for global growth could be derailed by market turbulence, the oil price crash and geopolitical conflicts. The agency has called on the G20 group to plan new mechanisms to protect the most vulnerable countries. Earlier this year, the IMF downgraded its forecast for global economic growth. It now expects economic activity to increase 3.4 per cent this year followed by 3.6 per cent in 2017.