A photograph by a Swedish coastguard aircraft of gas surfacing from a leak on the Nord Stream 1 pipeline. (Swedish coastguard/AFP/Getty Images)

The Nord Stream gas pipelines were damaged by two explosions, according to Danish officials during a NATO conference on Wednesday, each with the force of around 1,100 pounds (500 kilograms) of TNT, according to The Wall Street Journal, citing persons familiar with the case.

Russia's Nord Stream gas pipelines were struck in Danish waters near the island of Bornholm on Monday. The Swedish and Danish governments announced the discovery of two gas leaks caused by submarine explosions, with the general agreement being that the occurrence was the result of sabotage.

Earlier today, Russian Security Council Secretary Nikolai Patrushev stated on Friday at a meeting of the heads of intelligence agencies of the CIS countries, after the fourth explosion hit the Nord Stream pipelines, that the United States is the main beneficiary of the emergency situation.

"Literally from the first minutes after reports of explosions on the Nord Stream 1 and Nord Stream 2 gas pipelines, the West launched an active campaign to find those responsible. However, it is obvious that the main beneficiary, primarily economic, is the United States," Patrushev said.

In the same context, Russian Foreign Intelligence Service chief Sergei Naryshkin told reporters on Friday that Russia already holds proof that the West is accountable for the pipeline explosions. "We already have some materials that point to the Western footprint in organizing and carrying out this terrorist act," Naryshkin said. He expressed that the West does everything to "hide the true organizers and perpetrators of this international terrorist act."

During a phone call with Turkish President Recep Tayyip Erdogan on Thursday, Russian President Vladimir Putin called the incident an act of international terrorism against the Nord Stream gas pipelines.

The Russian Prosecutor General's Office opened an investigation into allegations of international terrorism in connection with the Nord Stream gas pipeline explosions. Dmitry Polyanskiy, Russia's Deputy Permanent Representative to the United Nations, said an emergency meeting of the UN Security Council to discuss the incident was scheduled for 19:00 GMT on Friday.

The Swedish National Seismic Network (SNSN) reported powerful underwater explosions in the area of gas leaks from the Nord Stream pipeline on September 27.

SNSN Director Bjorn Lund said as quoted by SVT that "there are no doubts that these were explosions."

“One explosion had a magnitude of 2.3 and was registered by dozens of monitoring stations in southern Sweden,” he stated.

“You can clearly see the waves bounce from the bottom to the surface," Lund added.

On his part, Peter Schmidt, an Uppsala University seismologist, said the Swedish National Seismic Network recorded two "massive releases of energy" shortly prior to, and near the location of, the gas leaks off the coast of the Danish island of Bornholm.

"The first happened at 2:03 am (0003 GMT) just southeast of Bornholm with a magnitude of 1.9. Then we also saw one at 7:04 pm on Monday night, another event a little further north and that seems to have been a bit bigger. Our calculations show a magnitude of 2.3," Schmidt said.

The Norwegian Seismic Array (NORSAR) also confirmed it had registered "a smaller explosion" in the early hours of Monday, "followed by a more powerful one on Monday evening."

Photos taken by the Danish military showed large masses of bubbles on the surface of the water emanating from the three leaks located in Sweden's and Denmark's economic zones, spreading from 200 to 1,000 meters (656 feet to 0.62 miles) in diameter.