South Korea said Monday it would start sending flood relief aid to North Korea next week despite tense ties, after a US aid shipment arrived in the communist state. "The first batch of our flood relief aid is expected to be delivered next week," said South Korea's Ministry of Unification spokesman Chun Hae-Sung. In early August Seoul offered flood aid worth five billion won ($4.7 million), including medicine, instant noodles, nutritious meals for children and other materials. But it rejected the North's request for food staples, cement and equipment for restoration work. South Korea has been reluctant to ship rice or cement for fear it could be diverted to the military. It was Seoul's first such offer since the North's deadly attack on a South Korean island last November sent relations into deep freeze. Ties turned icy when Seoul accused Pyongyang of torpedoing a warship in March 2010 with the loss of 46 South Korean lives. The North denied involvement in the sinking but shelled the border island last November, killing four people including two civilians. The North, which even in normal times struggles to feed its people, has reported dozens of casualties, thousands homeless and large areas of farmland flooded following a storm and torrential rain this summer. About 90 tonnes of emergency supplies sent by US-based Christian relief group Samaritan's Purse and funded by the US government arrived Saturday in the North. It includes blankets, plastic sheeting for shelters, hygiene kits, water filtration systems and medical supplies. For months Washington has been withholding a decision on sending separate food aid to the country until Pyongyang tackles US concerns over whether it will be distributed to the needy.