ROME, May 17 (Reuters) - Nine people died and thousands were evacuated from their homes as torrential rain battered Italy's northern Emilia-Romagna region, triggering floods and landslides, officials said on Wednesday.

Civil Protection Minister Nello Musumeci said some areas had received half their average annual rainfall in just 36 hours, causing rivers to burst their banks, sending water cascading through towns and submerging thousands of acres of farmland.

Sunday's Formula One Grand Prix in Imola, which is close to many of the worst-hit areas, was called off in an effort to relieve pressure on emergency services and prevent motor racing fans from converging on the inundated region.

"We are facing catastrophic events that have probably not been seen before," the president of the Emilia-Romagna region Stefano Bonaccini told reporters. "Extraordinary amounts of rain have fallen on land no longer capable of absorbing them."

The Adriatic coastal city of Ravenna, famed for its early Christian heritage sites, was badly affected. The local interior ministry representative said some 14,000 people would have to be evacuated from the area as soon as possible.

Authorities said flooding had hit 37 towns and communities and around 120 landslides had been registered. At least one bridge, near the city of Bologna, collapsed, some roads were undermined by floodwaters and many rail services were suspended.

Nine bodies had been retrieved from various locations, Bonaccini said. Irene Priolo, vice president of the region, told reporters that although the rains were easing, river levels were still rising.

Civil Protection Minister Musumeci said he would ask the cabinet to find 20 million euros ($22 million) for the affected area when it meets on May 23 to consider relief measures.

Government officials said tax and mortgage payments would be suspended for flood-hit regions during the emergency.