Large swathes of the United States suffered another day of extreme weather on Sunday, with hot temperatures in the nation's capital and Southeast coastal areas giving way to thunderstorms later in the day.

Powerful thunderstorms stretched through the states of Delaware, Maryland and Virginia on the Atlantic Coast, Accuweather said.

(Reuters) - Engineers monitoring BP Plc's damaged well in the Gulf of Mexico detected seepage on the ocean floor that could mean problems with the cap that has stopped oil from gushing into the water, the government's top oil spill official said on Sunday.

Earlier on Sunday, BP officials had expressed hope that the test of the cap which began Thursday could continue until a relief well can permanently seal the leak next month. Oil gushed from the deep-sea Macondo well for nearly three months until the new cap was put in place last week.

(Reuters) - The $15 billion U.S. Census is near completion with a response rate unchanged from a decade ago, defying concerns it might be derailed by anti-government sentiment and widespread violence against census takers.

Conservative figures like television commentator Glenn Beck and Republican Congresswoman Michelle Bachmann had urged Americans to provide only minimal information on the census form.

California (Reuters) - A white former transit police officer was found guilty of involuntary manslaughter in a videotaped shooting death of an unarmed black man last year in Oakland, California, sparking a wave of looting and destruction in the city on Thursday.

The verdict prompted a peaceful protest by up to 1,000 people in downtown Oakland, which gave way after nightfall to some people looting stores, smashing car windows, throwing powerful fireworks at police and lighting fires in trash cans.