The ultimatum, issued late on Friday, signals a possible escalation from the rebel group after their attacks tailed off in January following a ceasefire between Israel and Hamas in Gaza.
“We give the entire world notice: We are granting a four-day deadline,” the group’s leader, Abdel-Malik al-Houthi, said in a video statement.
“This deadline is to allow for mediators to continue their efforts. If, after these four days, the Israeli enemy persists in preventing the entry of aid into Gaza, maintains the complete closure of crossings, and continues to block the entry of food and medicine into Gaza, we will resume our naval operations against the Israeli enemy,” he added.
The Houthis launched more than 100 attacks targeting ships in the Red Sea and the Gulf of Aden following Israel’s war on Gaza, saying the raids were in solidarity with Palestinians in the enclave.
During that period, the fighters sank two vessels, seized another and killed at least four seafarers in an offensive that disrupted global shipping, forcing firms to re-route to longer and more expensive journeys around Southern Africa.
The Houthis also launched dozens of missile and drone attacks on Israel, killing at least one person and causing damage to buildings, including a school in Tel Aviv.
The United States, under President Donald Trump, re-designated the Houthis as a “terrorist” organisation earlier this week.
Hamas has welcomed the announcement.
“The brave decision … is an extension of the positions of support and assistance that they [the Houthis] provided over the course of 15 months of war … in Gaza,” the Palestinian group announced.
The Houthis, who control most of Yemen, also stated in February that they will take military action if the US and Israel try to displace Palestinians from Gaza forcibly.
Their ultimatum comes as Israel’s blockade on all aid into Gaza entered a seventh day.
The siege began on March 2 after Israel reneged on the ceasefire deal and sought to extend the first stage of the three-phased agreement that expired last week, without committing to ending the war on Gaza.
The United Nations, rights groups and countries around the world say the Israeli blockade could constitute a war crime.
The Office of the High Commissioner for Human Rights (OHCHR), in a statement on Friday, noted the Israeli action has caused prices to soar in Gaza and resulted in anxiety over a return to bombardment and starvation.
It added that the blockade also comes as health authorities reported that at least eight babies, whose families have been sheltering in flimsy makeshift tents, have died from the cold in the past two weeks.
“As the occupying power, Israel has a legal obligation to ensure the provision of the necessities of life for Palestinians living under its control,” the OHCHR said, stating, “Any denial of the entry of the necessities of life for civilians may amount to collective punishment. The use of hunger and starvation as a weapon of war is a war crime.”
Palestinians say the blockade has also resulted in shortages of medical supplies and left hospitals struggling to care for those wounded in the war.
Israel’s war on Gaza has killed at least 48,440 Palestinians and wounded 111,845 others. Authorities in the enclave say the death toll is likely to be at least 61,709, as thousands of Palestinians missing under the rubble are presumed dead.
