The rebels officially confirmed the death of their “president” on Monday, saying he was assassinated four days earlier along with six of his bodyguards in air raids launched by a coalition assembled by Saudi Arabia.
The coalition has been backing forces loyal to Yemen’s exiled President Abd-Rabbu Mansour Hadi in their fight against the Houthis.
A former teacher by profession, al-Sammad joined the political wing of the Houthis in the early 2000s after two of his brothers were killed in government-led air raids.
Rising through their ranks, he was elected leader of the Supreme Political Council in July 2016, after the Houthis established a government to administer the capital, Sanaa, and other areas they had previously seized.
Although he was not a military commander, al-Sammad would go on to hold the number two spot on the coalition’s most-wanted list, with the Saudis offering $20m for any information that would lead to his capture.
At the beginning of April, Sammad dubbed 2018 “the year of ballistic excellence”, vowing to launch at least one missile across the border every day in retaliation to Saudi-led air raids.
Despite his angry rhetoric, he was considered by many Yemenis to be a “moderate” who was willing to engage in peace talks and end the country’s three year-war that has killed at least 10,000 people and left 22 million Yemenis in dire need of humanitarian assistance.
The most senior member of the Houthis to die during the three-year conflict, al-Sammad’s killing was lamented by senior Houthi officials.
“This crime won’t go unanswered,” the rebels’ leader, Abdul Malek al-Houthi, warned in a televised speech on Monday.
“Neither this, nor other crimes like the targeting of a wedding in Hajjah province that left dozens dead and injured will go unanswered,” referring to an air attack that killed at least 20 people on Sunday.
No one really knows how their leadership moves ... so they may well have been compromised at the highest level and this could affect them going forward.
But with information about the whereabouts of the leadership tightly controlled, and only a handful of people informed of their movements, figures close to the Yemeni government were quick to suggest that the Houthis’ inner-circle had been compromised.
“Some people within the movement gave his location to the Saudi-led coalition,” claimed Colonel Abdul Basit Al Baher, the deputy spokesperson for Yemen’s army in Taiz.
“This is the president of the Supreme Political Council. His movements are secretive.”
Baraa Shiban, a Yemen analyst, echoed this view, saying that there appeared to be “big holes” in the Houthis’ security apparatus.
“This is a big hit for the Houthi movement,” he told Al Jazeera.
“No one really knows how their leadership moves … so they may well have been compromised at the highest level – and this could affect them going forward.”
Al-Sammad was crucial to the Houthis’ military propaganda, Shiban said, adding that his targeting could signal plans to launch a major assault on Hodeidah city.
Videos emerged on Friday of Tarek Saleh – the nephew of former ousted Yemeni leader Ali Abdullah Saleh, who was killed in December 2017, showing him preparing his fighters to launch an attack on the port.
“Hodeidah has witnessed an escalation in fighting over the last two weeks, and something this big [al-Sammad’s death] could indicate something bigger being planned,” said Shiban.
“There’s been a trend of Houthi field commanders being killed by the coalition, so to ensure that this incident does not affect the morale of their fighters on the front lines, the Houthis may attempt to fire more missiles into Saudi Arabia.
“His death could lead to an escalation by the Houthis.”
Just as they announced al-Sammad’s death, the rebels also said that he had been replaced by Mahdi al-Mashat.
“Mashat is a hardliner,” said Osama al-Rawhani, the programme director of the Sanaa Center for Strategic Studies.
“Sammad was good with building allegiances with tribes and non-Houthi factions, as well putting out fires within the Houthi movement.
“His death will have an impact within the Houthi movement which will be reflected on the ground.
“It may also serve a conduit for them to enact vengeance and that will put a temporary pause on the current peace negotiations.”
Earlier this month, Martin Griffiths, the newly appointed UN envoy to Yemen, said that he would develop a new framework to re-launch negotiations between the coalition and the rebels.
But a Houthi source told Al Jazeera that the air raids could derail the proposed talks.
“Mohammed Abdul-Salam [a senior Houthi leader] may continue to meet Saudi officials for peace talks in Oman, but we have a responsibility to avenge Sammad’s death,” the source said on condition of anonymity.
Peter Salisbury, a senior consulting fellow at UK-based Chatham House, downplayed al-Sammad’s role in the movement.
“In terms of his decision making power on a day-to-day basis, he was increasingly more of a figurehead than a major figure,” Salisbury told Al Jazeera.
“Sammad came from the Houthis political wing and as the war continued, the military wing, the more extreme wing of the movement, took over,” Salisbury said.
“What we’re seeing now is the winnowing out of many political figures and the consolidation of military hardliners,” he added.