The largest number of complaints - around a hundred - were about television footage of a man being resuscitated shortly after a bomb blast.
Viewers found the pictures very upsetting. Some were concerned that if family and friends saw them they would have been extremely distressed.
The BBC responded immediately that inclusion of the footage had been an accident and it would not be shown again.
Graphic mobile images
Complaints were also received about the use of mobile phone images and video clips sent in by members of the public who witnessed the bomb scenes.
Comments ranged from concerns that the images were too graphic and intrusive to criticisms that the mobile network would be jammed at a time when people were desperate to keep in contact.
Head of BBC News, Helen Boaden, responded that great care was taken over the selection of images, which had added greatly to the reporting of the day's events.
"The pictures submitted by the public were so good, live and relevant that we were able to use them right across our coverage." she said.
The BBC has used "user-generated material" in the past - for instance during the Asian Tsunami and the Boscastle floods. But the response to events on July 7 was unprecedented.
The BBC received around 50 images from the public within an hour of the first blast and this rose to more than a thousand within 24 hours.