It was an audacious plot sketched in chilling detail with blue pens on the back of a paper calendar: Islamic militants in the Philippines, including one of the world’s most-wanted militant leaders, would take over a key southern city in their boldest attack to date.

With unsettling calm, they spoke of taking hostages from a school, sealing off roads and capturing a highway “so the people will get scared.”

Video footage and a separate screen-grab image of that secret meeting, obtained exclusively by The Associated Press, offer a rare glimpse into the clandestine operations of insurgents who followed through two weeks ago with an unprecedented assault on the lakeside city of Marawi, parts of which they still occupy today.

The images also provide the first visual proof that a nascent alliance of local Muslim fighters is not only aligned with the Islamic State group, but coordinating and executing complex attacks together. Among those at the table was the purported leader of the Islamic State group’s Southeast Asia branch, Isnilon Hapilon, who is on Washington’s list of most-wanted terrorists and has a $5 million bounty on his head.

The footage is believed to be the first of Hapilon since he and several other Filipino militants pledged allegiance to IS in 2014. The military had said he was wounded in a January airstrike; in the video, however, there are no indications that he is injured. Hapilon appears sitting with other militants at a table, wearing a yellow and black headscarf with a pistol beside his folded arms.

Military chief of staff Gen. Eduardo Ano confirmed the identities of those present, including Hapilon, who resembles other images said to be of him, such as those on FBI wanted posters. The militants have no spokesman and do not generally issue statements.

The images show that the insurgent alliance “has this intention of not only rebellion, but actually dismembering a portion of the Philippine territory by occupying the whole of Marawi city and establishing their own Islamic state or government,” said Ano.

The military has an interest in allowing the AP to make the footage public. On Monday, six lawmakers petitioned the Supreme Court to nullify President Rodrigo Duterte’s imposition of martial law in the south — homeland of minority Muslims in the largely Roman Catholic country — casting doubt on the gravity of the crisis there. Ano said the reality that “a full-blown rebellion” is underway should convince skeptics that this is not just “a small problem.”

Government troops discovered the video on a cellphone they seized during a May 23 raid on a Marawi safe house where Hapilon and other militants were believed to be hiding. They said the video had been filmed a day or two earlier. It was not possible to independently verify that claim. But a separate screen grab of the same meeting, obtained by the AP from an anti-terrorism agent, showed the militants were writing on a calendar dated 2017.

An army official allowed the AP to record the video as it played on a laptop computer.

Ano said the insurgents had been planning to attack Marawi on May 26, the start of Ramadan in the south. But the raid cut their preparations short and triggered instant clashes. Had the assault not been pre-empted, the militants likely would have seized more territory and inflicted far more damage.

As it stands, the fighting has been unprecedented; while militants have launched major attacks before, never before has any group occupied territory in the heartland of the Philippines’ Islamic faith for this long. Two weeks after the conflict began, at least 178 people have been killed and the army is still battling to regain control with airstrikes and artillery.

The militants, who are believed to be holding a Catholic priest and many other hostages, have torched buildings and destroyed at least one church. Ano said they occupy 10 percent of the city and have positioned snipers in tall buildings. Much of the city center has been devastated.

The crisis in Marawi, combined with fears that the Islamic State group is breathing new life into Muslim insurgencies in Southeast Asia, has put the Philippines and the region on edge.

On Friday, when a masked gunman began shooting and burning gambling tables in a Manila casino, terrified patrons immediately assumed an Islamic State siege was underway. The radical group claimed responsibility for the attack, in which dozens of people died of smoke inhalation, but there has been no evidence to back its claim. Police insist the motive was robbery, and the gunman’s family says he was a disgruntled gambling addict.

Still, the episode highlighted what House Speaker Pantaleon Alvarez described as the “unsettling inadequacy” of public security in the capital. The attack, he said, should “serve as a wake-up call” to do something about it.

A security conference this past weekend in Singapore attended by defense ministers and experts from 39 nations produced a flurry of alarmed statements. Among the topics: a fear that places like Marawi could become a new base for the Islamic State group as it loses territory in the Middle East.

“If the situation in Marawi in the southern Philippines is allowed to escalate or entrench, it would pose decades of problems,” said Singapore Defense Minister Ng Eng Hen. “All of us recognize that if not addressed adequately, it can prove a pulling ground for would-be jihadists.”

The southern Philippines already is.

Of the 120 militants killed in Marawi so far, at least eight are known to be foreign fighters, including a Chechen, a Yemeni and several Malaysians and Indonesians, according to Defense Secretary Delfin Lorenzana.

Hapilon’s pledge of allegiance, meanwhile, may have already paid off. His faction has received a “couple of million dollars” from the Islamic State, Lorenzana said.

In the video clip obtained by the AP, which runs for just over two minutes, a long-haired man identified by the military as Abdullah Maute addresses other militant leaders gathered around a white plastic table.

Pointing to a crude sketch of Marawi’s main streets and speaking in Tagalog and Marawi’s Maranao dialect, he declares, “We’ll take this first and then here.”

“Or,” he says, “we can go here first. We seal this off so you’ll have a passageway. But we need to capture a highway so the people will get scared.” Another militant can be seen videotaping the clandestine meeting.

Maute is the leader of a militant group called the Islamic State Ranao — one of about 10 small armed Muslim groups that have also pledged allegiance to the Islamic State and have forged a loose alliance that now flies IS-style black flags.

Although virtually unheard of a few years ago, they contributed over 260 of the fighters who attacked mosque-studded Marawi, the military says. Along with Hapilon’s group, they were blamed for a night market bombing in September that killed 15 people in the southern city of Davao, Duterte’s hometown.

Also appearing in the video clip are two of Maute’s brothers — Omarkhayam and Maddi — and another militant known as Abu Humam. Humam is a member of Khilafah Islamiyah Mindanao, a small group linked to a 2013 bombing that killed eight people in a bar in Cagayan de Oro, not far from Marawi.

The new armed groups are the latest offshoots of a decades-long Muslim separatist conflict fueled by wrenching poverty, weak law enforcement and a surfeit of weapons in the southern Philippines. The two biggest Muslim rebel groups, which have engaged in peace talks with the government, have not backed the militants who attacked Marawi and offered to help end the siege.

Hapilon’s militant alliance aims to establish a “wilayat,” or a provincial territory, that will form part of a caliphate in Southeast Asia, according to experts. Duterte says government forces will never allow them to do that or break away from the Philippines. (Associated Press)