For up to seventeen hours from Saturday night through to Sunday, scores were slaughtered, shot or hiding for their lives as six Taliban operatives stormed Kabul’s luxury Intercontinental Hotel – with fingers pointing to an attack likely carried out with inside help.

According to multiple officials and sources on the ground, three of the attackers entered the luxury hotel through the VIP-only access gate, which is reserved for government officials and high-ranking diplomats only, in an armored SUV. Such an entrance requires a pre-clearance and a rarely-distributed VIP pass issued by hotel administration, one official said, and thus much of the hefty security measures – including additional scans and checks – are then bypassed.

“Without having help from the inside, there is no way passing through four checkpoints would have been possible,” Sanjar Sohail, a Kabul-based investigator and publisher of the Hasht e Subh newspaper, told Fox News.

The well-dressed attackers then were said to be able to enter the hotel through the kitchen – thus bypassing the standard body-scanning procedure – and launch their shooting rampage, seeming to know the layout of the hotel in detail.

The two additional assailants, who had been dining in the restaurant, then joined the shooting fray. Appearing calm and collected, according to eyewitness recollections, they politely finished their food before opening fire, reportedly killing two children. They then moved through the hotel room-by-room with the intent to kill.

“They knew where foreign nationals were staying and avoided some rooms,” one source said.

Reports of how many people died still varied widely on Sunday, with an Afghanistan government official saying more than 40 people were killed while other government spokespeople said only five civilians died.

Afghan police also suspected that the two diners had been in the hotel for days, but it was not clear whether they had a room booked or were hiding out in an undisclosed area.

“They had access to rooms, the guest floors. They went through doors that have special access codes that are computerized,” one Afghan law enforcement source said. “It seems that they had no trouble using those codes.”

Feroz Bashari of the Afghan government’s Media and Information Center told Fox News the matter is under full investigation, and concurred that it appeared so far the attackers “had inside help from the hotel.”

Taliban spokesperson Zabihullah Mujahid promptly claimed responsibility for the attack, claiming that they initially intended to strike on Thursday but postponed the onslaught to Saturday evening in a quest to minimize civilian casualties due to a wedding that was taking place during the initial target time.

INSIDE DEADLIEST TALIBAN ATTACK AGAINST AFGHAN TROOPS

The brutal attack on the hotel, popular with foreign journalists and diplomats, came as the security situation in the Afghan capital and country-wide has been crumbling, prompting the Trump administration to deploy more troops and more weaponry to combat the escalating violence.

Security specialists affiliated with prominent local private security company Kabul Balkh Safety & Security Company (KBSS), which took over security duties for the hotel from the Afghan government just 21 days ago, insisted to Fox News that all safety protocols and procedures were met, and that some of the weapons had been placed inside the hotel in advance of the attack.

“The Taliban have become very skilled and using the internet and other devices for collecting intel, and it is easy for them to get fake identification cards, uniforms and vehicles prior to carrying out attacks,” noted Ahmad Muslem Hayat, a security professional and former military attaché at the Afghanistan Embassy in London.

AFGHANISTAN'S WAR HOSPITALS: CHILDREN LEFT FOR DEAD AMID ESCALATING VIOLENCE

More than 100 IT managers and information technology professionals were on-site for a Sunday conference, and many attendees are believed to be among the dead and wounded, along with high-profile members of the Peace Council for Kandahar who were meeting with other local leaders from Helmand province.

Karachi-based Afghanistan Consul General Dr. Abdullah Waheed Poyan was among the dead. He served as Afghanistan’s consul in Peshawar for two years before being rotated to the same role in Karachi last year. He was known for his tenacious diplomatic and efforts for peace between the two countries, a devoted academic and political analyst. During the Afghan war, Poyan escaped to the U.S. – where his family still lives – but he later returned to continue work in Afghanistan.

Several friends of Poyan claimed he also became a U.S. citizen, but the State Department was not able to immediately confirm or deny that. U.S. diplomats in Kabul are “monitoring the situation and are in contact with local authorities to determine if any U.S. citizens have been affected,” officials said.

Afghan intelligence sources told Fox News that Poyan was not liked by the Taliban, and the possibility that they accessed his name and room number, along with an additional guest list, was being heavily scrutinized.

The Afghan National Defense Security Forces led the response efforts, a U.S. military spokesperson at the Kabul Resolute Support headquarters – the name given to the NATO-led Afghanistan mission – told Fox News, adding that U.S. forces in the country “provided hostage rescue advising assistance and were standing by to provide media evacuation assistance to the Afghan Security Forces on the scene.”

“We condemn the despicable attack on civilians at the Intercontinental hotel in Kabul. The terrorists responsible for this cowardly attack are enemies of Afghanistan. On behalf of the entire Resolute Support Mission, our thoughts go out to the family and friends of the innocent people murdered and wounded in this incident,” General John Nicholson, Resolute Support commander told Fox News in a statement. “The international community stands with the legitimate government of Afghanistan as it works to secure the Afghan people and build a stable and peaceful future for all Afghans.”

All five attackers were killed, interior ministry spokesperson Najib Danesh said.

The Taliban, which had been in the midst of peace negotiations in Turkey this past week, also attacked the Intercontinental six years ago, killing 21.

Mir Jalalzai contributed to this report.