A nonprofit institution that focuses on stopping the spread of nuclear weapons on Monday night released what appears to be satellite images of North Korea`s rocket in flight, CNN reported.

The communist nation launched the rocket last weekend in defiance of international opposition.

The Washington-based Institute for Science and International Security said it obtained the images from a DigitalGlobe satellite and that they were taken Sunday in North Korea.

In one image, the missile`s exhaust plume can be seen. The flame from the burning propellant appears as a solid white mark.

The terrain below the rocket in a second image is only a few kilometers away from the launch pad, the institute said.

The third image is a close-up of the flame from the rocket`s burning propellant, the institute said.

CNN could not independently confirm the information provided by the institute, led by former U.N. nuclear inspector David Albright.

North Korea has described the launch -- which flew in the face of numerous international warnings -- in celebratory terms. State-run media KCNA said North Korean leader Kim Jong-Il expressed "great satisfaction" at seeing the launch of the rocket carrying a communications satellite.

Not only did the country successfully send a communications satellite into orbit, KCNA said, but "it is sending to the Earth the melodies of the immortal revolutionary paeans `Song of General Kim Il Sung` and `Song of General Kim Jong Il.` "

The United States and other nations say the move demonstrated the country`s ability to shoot a long-range missile -- a rocket with a warhead attached -- and violated U.N. Security Council resolutions.