CHICAGO (Reuters) - Chicago police trying to keep the peace during the NATO summit may face their biggest test on Sunday when thousands of demonstrators were expected to march near the site where leaders of the military alliance begin a two-day meeting. Previous protests in the runup to the summit Sunday and Monday have been lively but peaceful, resulting in fewer than two dozen arrests over the past six days, according to the Chicago Police Department. ...

MIAMI (Reuters) - Tropical Storm Alberto churned slowly toward the South Carolina coast on Sunday where heavy rain and dangerous surf are expected from the beach resort of Myrtle Beach south to Savannah, Georgia, forecasters at the U.S. National Hurricane Center said. Bringing an early start to the Atlantic hurricane season, Alberto rose to tropical storm strength on Saturday and by Sunday morning was about 95 miles south-southeast of Charleston, according to the latest update by the hurricane center in Miami. It carried maximum sustained winds near 50 miles per hour. ...

PHOENIX (Reuters) - Improving weather helped firefighters in Arizona make progress on Saturday against wildfires that have charred more than 65 square miles (168 square km) of forest, brush and grass in the U.S. Southwest and forced the evacuation of several small towns. More than 2,000 firefighters were battling five blazes in Arizona and Colorado from the ground and air. Meanwhile, a small blaze in New Mexico's Gila Wilderness area ballooned in size as wind whipped the flames. ...

The launch of a privately owned Falcon 9 rocket from Cape Canaveral Air Force Station was delayed on Saturday when a computer detected a possible problem with one of the rocket's engines, a Space Exploration Technologies official said. Preparations for the company's trial cargo run to the International Space Station proceeded smoothly until 4:55 a.m. EDT (0855 GMT) when an onboard computer aborted the launch. "Liftoff ... we've had a cutoff. ...