Financial Times: Wheat prices rose further on Friday in the wake of Russia’s decision to extend its grain export ban by 12 months, raising fears about a return to the food shortages and riots of 2007-08. In Mozambique, where a 30 per cent rise in bread prices triggered riots on Wednesday and Thursday, the government said seven people had been killed and 288 wounded. Vladimir Putin’s announcement on Thursday extended an export ban first introduced last month until late December 2011, sending …