Boston Marathon begins amid heavy security
- 1/8
A Boston Police bomb detection dog sits near the finish line of the 118th Boston Marathon Monday, April 21, 2014 in Boston. (AP Photo/Robert F. Bukaty)
- 2/8
A military police officer salutes during opening ceremonies of the 118th Boston Marathon Monday, April 21, 2014 in Hopkinton, Mass. (AP Photo/Steven Senne)
- 3/8
Police officers give a rundown of the scene at Wellesley College to a State Police Special Response team before the start of the 118th Boston Marathon Monday, April 21, 2014 in Wellesley. (AP Photo/Mary Schwalm)
- 4/8
Boston Police officers on bicycles ride across the finish line before the 118th Boston Marathon Monday, April 21, 2014 in Boston. (AP Photo/Elise Amendola)
- 5/8
A heavy police presence stand guard in Boylston Street near the finish line of the Boston Marathon
REUTERS - 6/8
Boston Police officers receive instructions from their supervisor near the finish line before the 118th Boston Marathon Monday, April 21, 2014 in Boston. (AP Photo/Robert F. Bukaty)
- 7/8
Massachusetts State Police and military police gather before the start of the 118th Boston Marathon Monday, April 21, 2014 in Hopkinton, Mass. (AP Photo/Michael Dwyer)
- 8/8
A Boston police officer and security dog pass by the photo bridge at the finish line for the 118th Boston Marathon Monday, April 21, 2014 in Boston. (AP Photo/Elise Amendola)
The 118th running of the Boston Marathon has begun amid heavy security a year after the bombings near the race's finish line that killed three people and wounded more than 260 others.
The race began at 8:50 a.m. Monday for mobility-impaired marathoners and at 9:32 a.m. for elite women. The elite male runners start at 10 a.m.
— Associated Press