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) - An Iranian nuclear scientist who says he was abducted by CIA agents a year ago returned home from the United States early on Thursday saying he was pressured to lie about Iran's nuclear programme.

Washington denied kidnapping Shahram Amiri and insisted he had lived freely in the United States. A U.S. official said, however, that the United States, which suspects Iran of secretly developing nuclear weaponry, had obtained information from him.

(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.

Pakistan (Reuters) - A suicide bomber on a motorbike killed up to 45 people and wounded dozens in an attack outside the office of a senior government official in Pakistan's northwest on Friday, government and hospital officials said. The bomber struck when people were gathered around the office in the Mohmand ethnic Pashtun tribal region on the Afghan border, where security forces have stepped up attacks on Taliban militants in recent weeks.

"There were two blasts. The first one was small but the second was a big one. Up to 45 people have been killed," Rasool Khan, the region's assistant political agent, told Reuters. The attack took place outside his office.

An administration official, Mehraj Khan, had earlier described the incident as a suicide attack, but there were no details available on how the second blast happened.

Hospital officials said nearly 80 people were being treated for multiple wounds, while government officials put the number of wounded at about 40.

Among the wounded were several internally displaced people, who were collecting relief goods near the blast site.

Thousands of people have been uprooted by the militant violence and security forces' operations in the northwestern region.

"I was standing about 200 yards (meters) away from the office when I heard the blast. I don't know how it happened but I could see several bodies lying on the ground after the explosion and people running in all directions," said Riaz Hussain, a witness.

Television footage showed victims being pulled out of the debris. The blast also damaged several cars and about 30 shops, witnesses said.

A security official at the scene said the blast also damaged a nearby prison wall and several inmates had escaped.

Pakistan launched two major offensives in the northwest last year against homegrown Taliban militants who have killed hundreds of people in retaliatory attacks across Pakistan, mostly in the northwest, but also in major cities.

Two suicide bombers killed at least 42 people in an attack on Pakistan's most important Sufi shrine in the eastern city of Lahore last week.

The Pakistani Taliban, allies of the Afghan Taliban, have lost ground in army offensives over the past year.

They were pushed out of the Swat valley, northwest of Islamabad, and in October the army began an offensive in the militants' South Waziristan bastion on the Afghan border.

The offensive was extended to Orakzai in March as many of the militants who fled the South Waziristan operation took refuge there and in Mohmand. Hundreds of militants have since been killed in air strikes in the two regions.

Jet fighters killed about a dozen militants in attacks in Orakzai on Friday, security officials said. There was no independent verification of the casualties as militants often dispute and reject official figures.

(Writing by Augustine Anthony; Editing by Chris Allbritton and Sugita Katyal)

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.

(Reuters) - Toyota Motor Corp said on Tuesday it had received reports more than three years ago of faulty engine valve springs at the center of a U.S. recall of nearly 139,000 luxury Lexus vehicles it announced last week.

Toyota plans to recall 270,000 luxury Lexus and Toyota Crown vehicles across the United States, Japan, Canada, Australia, Europe and other countries due to the potential defects that could lead to engine failures.

(Reuters) - The head of oil major Total warned of tougher safety rules that could push up crude prices as the first storm of the Atlantic hurricane season compounded the impact of the Gulf of Mexico oil spill.

The storm cast more crude into beaches and marshes and left BP Plc unlikely to resume cleanup efforts for a fourth day.