ISLAMABAD (Reuters) - Heavy monsoon rains in Pakistans southern Sindh province have caused only minor damage to the sugarcane and rice crops, officials said on Tuesday, though weeks of heavy downpour have already destroyed about 13 per cent of the cotton crop. The floods have made about 280,000 homeless, and ruined crops over 1.7 million acres of land in Sindh, where the cotton crop has been hit the hardest, with an estimated loss of up to two million bales. Officials said the recent floods have damaged or destroyed rice crops in a few districts of Sindh, but the country still expects a bumper crop of up to 6.5 million tonnes, thanks to timely rains in Punjab, the countrys main agricultural province. At this point, we are estimating that roughly 15 percent of the rice crop in Sindh has been damaged, said Taufiq Ahmed Khan, vice chairman of the Rice Exporters Association of Pakistan (REAP). But any further rains next week may increase the losses. Sindh was expected to produce about 2 million tonnes of milled rice this year. The worlds fifth largest rice exporter, Pakistan is hoping to export up to 4.5 million tonnes of rice in the 2011/12 fiscal year, and Khan said that target was still very much achievable. Rice exports fell to 3.7 million tonnes in the 2010/11 year, after floods in summer 2010.