From London to Sochi to Rio de Janeiro, the deadly bomb attacks on the Boston Marathon raised new concerns Tuesday over safety at major sports events around the world, including the Olympics and World Cup.

The twin bombings near the marathon finish line that killed three people and injured more than 170 people brought into sharp focus the security challenges facing next year's Winter Olympics in Sochi, Russia, the 2014 World Cup in Brazil and the 2016 Summer Games in Rio.

Wales will have two teams in next season's Premier League after Cardiff gained promotion to the lucrative top flight on Tuesday for the first time in 51 years.

Cardiff, which was playing in the fourth tier and suffering severe financial hardship only 11 years ago, guaranteed a top-two finish in the League Championship thanks to its 0-0 draw against Charlton.

An envelope addressed to a Republican senator tested positive Tuesday for ricin, a potentially fatal poison, congressional officials said, heightening concerns about terrorism a day after a bombing killed three and left more than 170 injured at the Boston Marathon.

One senator, Claire McCaskill of Missouri, said authorities have a suspect in the fast-moving ricin case, but she did not say if an arrest had been made. She added the letter was sent from an individual who frequently writes lawmakers.

The FBI's investigation into the bombings at the Boston Marathon was in full swing Tuesday, with authorities serving a warrant on a suburban Boston home and appealing for any private video, audio and still images of the blasts that killed three and wounded more than 170.

President Barack Obama said it was unclear whether the bombings were carried out by an international organization, domestic group or a "malevolent individual."

A powerful earthquake struck southeastern Iran on Tuesday, killing at least 34 people across the border in Pakistan and shaking buildings as far away as the Gulf and New Delhi.

The quake, measured at magnitude 7.8 by the U.S. Geological Survey, damaged hundreds of mud-built buildings in remote southwestern Pakistan and comes a week after another struck near Iran's Gulf port city of Bushehr, killing at least 30 people.

The Los Angeles Lakers' locker room had several conspicuous absences Sunday night. Kobe Bryant was at home after surgery on his torn Achilles tendon, and Steve Nash hasn't played in seven games.

Although Bryant's season is over, Dwight Howard insists the Lakers' fun has just begun.

The Miami Heat, resting LeBron James and most of their top players for the playoffs, earned a 96-95 win over the Cleveland Cavaliers on Monday.

Norris Cole stripped Kyrie Irving of the ball with 2.2 seconds left to give to give the Heat the win, finishing with 18 points, 11 rebounds and nine assists.

South Korea's government announced a $15.3 billion stimulus plan Tuesday to boost slowing growth in Asia's fourth-largest economy.

The stimulus would be South Korea's third-largest supplementary budget ever, exceeded only by those approved after the 1998 Asian financial crisis and the 2008 global financial turmoil when measured as a proportion of gross domestic product.

A U.S. judge whose smartphone disrupted a hearing in his own courtroom has held himself in contempt and paid $25 for the infraction.

Judge Raymond Voet has a posted policy stating that electronic devices causing a disturbance during court sessions will result in the owner being cited with contempt, the Sentinel-Standard of Ionia and MLive.com reported.

The twin blasts that killed three people and injured scores at the Boston marathon are a warning for Russia as it prepares to host the 2014 Winter Olympic Games, the sports minister said on Tuesday.

"For Russia, which will have to soon stage a number of major sporting events, this is a serious warning bell," RIA Novosti quoted Vitaly Mutko as saying.