New U.S. Intelligence is suggesting that a bomb planted by ISIS or an affiliated organization caused the crash of Russian Metrojet Flight 9268. The official who relayed the intelligence emphasized that, although a formal consensus on the matter has not been reached there is a strong suggestion that an explosive was planted on the plane.

This information was given to Barbara Starr of CNN. The source said that the information is based off of intelligence reports gathered before the crash, Saturday, and after. There were no credible reports or verifiable intelligence prior to the crash. The source did note that “additional activity in Sinai” had garnered some attention.

Another U.S official said intelligence on ISIS is based partly on internal messages that are under surveillance. Those messages are different than those made public.

Once the crash raised suspicions of a potential terrorist act, flights that neared the region were suspended in Ireland and the United Kingdom. The delay in the U.K. was implemented as a precautionary measure, once an explosive was named as the cause of the crash.

The Sinai peninsula, where the crash took place, has been a location of conflict between ISIS, related militant groups, and Egyptian forces. Militants took credit for the crash, according to a statement. Officials in Russia and Egypt debunked the claim, saying that there was no evidence of the crash being an act of terror. Egypt did not take action to increase security at the airport or surrounding areas, due to the lack of credible evidence.

The U.S Embassy in Cairo, however, did notify its employees, via a security message, advising them not to travel to the Sinai region during the investigation.