NEW: AP Source: 8-year-old among dead in Boston blast
BOSTON (AP) - A person familiar with the situation tells The Associated Press that an 8-year-old-boy has been killed in the explosions near the finish line of the Boston Marathon.
Police say three people were killed in the blasts. They provided no details, but someone who spoke to a friend of the family and spoke to the AP on condition of anonymity to protect the family's privacy confirmed that an 8-year-old boy was among the dead.
The person said the boy's mother and sister were also injured as they waited for his father to finish the race.
The explosions injured at least 144 people, 17 critically.