Flash floods triggered by Typhoon Muifa have killed at least 25 people in central Vietnam, state-run Vietnam Television said on Saturday. Torrential rains hit the region this week and floods submerged more than 10,000 houses and brought traffic to a standstill. "A red alert has been issued as floodwater is rising in all rivers in the area," a disaster management official from the coastal province of Quang Ngai said. Vietnam is the world's largest producer of robusta coffee, but no damage was reported to the Central Highlands coffee belt. Television reports said the rain should stop by late Saturday and floods in the regional rivers were expected to start receding from Sunday. State weather forecasters said floodwater levels in the Thach Han river in Quang Tri province, around 600 km (372 miles) south of the capital Hanoi, had peaked at a year high of 5.65 metres (18.54 feet) early on Saturday morning. Weather forecasters reported only mild, occasional rains in the Central Highlands coffee belt. "The sprinkle has not affected the coffee harvest yet. There might be some delay to the beans-drying process," said a coffee trader in Daklak, Vietnam's key coffee growing province. Typhoon Muifa, downgraded to a tropical storm, had shifted from Vietnam into the Gulf of Thailand by Thursday. The Southeast Asian country is normally hit by seven to eight tropical storms each year which trigger flash floods in the central region. In October and November last year nearly 100 people were killed in floods.