The British-based Reuters news agency has been stung for the second time by charges that it edited politically sensitive photos in a way that casts Israel in a bad light. But this time Reuters claims it wasn’t at fault.

The news agency reacted to questions raised by an American blogger who showed that Reuters' photo service edited out knives and blood traces from pictures taken aboard the activist ship Mavi Marmara during a clash with Israeli commandos last week. Nine people were killed and scores were injured in the clash.

The pictures of the fight were released by IHH, the Turkish-based group that sponsored the six-ship fleet that tried to break Israel's blockade of Gaza.

In one photo, an Israeli commando is shown lying on the deck of the ship, surrounded by activists. The uncut photo released by IHH shows the hand of an unidentified activist holding a knife. But in the Reuters photo, the hand is visible but the knife has been edited out.

The blog “Little Green Footballs” challenged Reuters' editing of the photo.

“That’s a very interesting way to crop the photo. Most people would consider that knife an important part of the context. There was a huge controversy over whether the activists were armed. Cropping out a knife, in a picture showing a soldier who’s apparently been stabbed, seems like a very odd editorial decision. Unless someone was trying to hide it,” the blog stated.

In a second photo the unedited print issued by IHH showed blood along the ship's railing and a hand holding a knife as an Israeli soldier lies on the deck. Both the blood and the knife were missing in the photo that Reuters released.

Reuters on Tuesday denied it intended to alter the political meanings of the photographs.

“The images in question were made available in Istanbul, and following normal editorial practice were prepared for dissemination which included cropping at the edges," the news agency said in a statement. "When we realized that a dagger was inadvertently cropped from the images, Reuters immediately moved the original set as well."

Reuters has yet to respond to charges about the second photo.

This is the second time Reuters has been accused of manipulating photos. In 2006 a Reuters photographer, Adnan Hajj, doctored several photos of the destruction caused by Israel's bombing of Beirut. In one he added smoke to a panoramic picture of South Beirut to make the damage look more severe than it was. In a second photo, he showed a woman whose home had supposedly been destroyed in the same raid, but an investigation revealed that the woman's house had been destroyed prior to the Israeli strike.

Reuters later removed all of Hajj's more than 900 photos from distribution and severed its relationship with him. A photo editor also was fired.

What happened on the Mavi Marmara and who was responsible for the killing and bloodshed on the ship is still a matter of debate. Activists charge that Israeli commandos fired first and provoked the skirmish. Israeli commandos say they were compelled to use deadly force after they were attacked by people on board the ship.