Cyclones wreak havoc in Australia

(Reuters) - Tens of thousands of Australians hunkered down on Friday as a powerful cyclone crossed the northeast, damaging houses, bringing down trees, cutting power lines and causing flash flooding, while a second storm made landfall to the west.

The major storm caught Queensland state almost unawares after it intensified in just a few hours before slamming into the coast midmorning as a category 5 system - the highest rating.

Emergency services scrambled to evacuate thousands of homes in the direct path of Cyclone Marcia before pulling out and warning anyone who had not left to barricade themselves inside to avoid wind gusts peaking at 285 kph (177 mph).

Rail lines to coastal ports, an essential part of Queensland's A$280 billion ($218 billion) commodities export-driven economy, were brought to a standstill.

"Stay indoors, don't go outside," Queensland Premier Annastacia Palaszczuk told a news conference as the storm passed over the coastal town of Yeppoon, home to 16,000 people about 550 km (340 miles) north of the state capital, Brisbane.

She warned the 75,000 residents of Rockhampton, just south of Yeppoon, that Marcia still posed great danger even though it had weakened to a category 3 system: "The eye of the storm is heading directly towards you."

Meteorologists said the worst of the winds should ease by Friday afternoon local time but warned heavy rains and flooding were likely to continue for several days and extend inland.