KABUL/WASHINGTON — At least six people are dead and 60 are wounded and, according to Emergency, a trauma center in Kabul following two explosions, one just outside the Hamid Karzai International Airport in Kabul and another at the nearby Baron Hotel.

Among the killed are four US Marines. Pentagon press secretary John Kirby tweeted that he can confirm that "a number" of US service members have been killed in the airport attack.

The attacks came less than a day after the US Embassy warned US citizens to get out of the area. The attack is "definitely believed" to have been carried out by the Daesh (so-called IS) group, a US official told The Associated Press.

The official also said "a number of others" are being treated for wounds. He noted that the US is also aware that Afghans "fell victim" to this attack. He did not provide exact numbers.

The Pentagon had earlier confirmed there was an explosion near a gate at Kabul's airport that "resulted in an unknown number of casualties." According to initial reports, there are some US personnel among the wounded.

Back in the US, some lawmakers tweeted about the explosion and the developing situation. Republican Sen. Mitt Romney described the attack as "horrific," saying that his "heart breaks" for the wounded.

Other Republicans blamed the White House with House GOP lawmaker Lisa McClain saying, “Americans are dying at the hands of President Biden's catastrophic withdrawal," and Rep. Jim Banks referenced "Biden's incompetence."

House Minority Leader Kevin McCarthy called on President Biden to take "decisive action to protect our troops, our citizens, and our allies without regard for an arbitrary deadline.”

McCarthy also urged House Speaker Nancy Pelosi to act quickly to brief Congress on the blasts near the Kabul airport.

“It is time for Congress to act quickly to save lives. Speaker Pelosi must bring Congress back into session before Aug. 31 so that we can be briefed thoroughly and comprehensively by the Biden Administration and pass Representative Gallagher’s legislation prohibiting the withdrawal of our troops until every American is out of Afghanistan," the California Republican said in a statement.

McCarthy extended his condolences to the families of those injured and killed in the attacks. “Today’s attacks are horrific. My prayers go out to those who were injured and the families of those who were killed.

“I also continue to pray for the safety of our troops, the stranded American citizens, our allies and Afghan partners who remain in the area. Our enemies have taken advantage of the chaotic nature of the withdrawal," he said.

Republican Rep. Adam Kinzinger said the two explosions that took place near Kabul’s Hamid Karzai International Airport should serve as a “reminder to Americans that when it comes to war, it's not just one side that can decide if they want that war to end.”

Kinzinger said members of Congress were in a briefing this week and “were warned of this exact threat.” He said that while “there’s no good answer to this,” if President Biden does not respond to the explosions, it could embolden terrorist groups.

“The Taliban have acted like they're going to secure the perimeter [of the airport]. They obviously did not. So I think there's a case for the United States to make that we are not leaving until all Americans and all the Afghans that are SIVs that we've promised are safe, and we will go outside of the gate to get them if necessary,” he said.

Kinzinger said the Biden administration should double-down on intelligence in place to monitor threats. “If we leave now without following through on our mission and our commitment to Americans and our Afghan partners, that will actually do more damage than any suicide bomb did today,” he said.

US officials believe ISIS-K was likely behind the attack at Kabul airport but are still working to confirm the terror group’s involvement, according to a senior US official and another source briefed on initial assessments.

On Wednesday, CNN reported that concerns about security around Hamid Karzai International Airport in Kabul have increased based on "a very specific threat stream" from ISIS-K about planned attacks against crowds outside the airport

The US believes ISIS-K, which is a sworn enemy of the Taliban, wants to create mayhem at the airport and has intelligence streams suggesting it is capable and planning to carry out multiple attacks, a defense official told CNN Wednesday. — CNN with input from agencies