Senior figures from Hamas and Yemen's Houthi rebels held a rare meeting to discuss coordinating their actions against Israel, Palestinian factional sources told the media on Friday.
Hamas and the Houthis belong to the "axis of resistance", a collection of Iran-backed movements hostile to Israel and the United States that also includes Lebanon's Hezbollah and Iraqi militias.
The Houthis have attacked Red Sea shipping for months since the Israel-Hamas war broke out on October 7, saying they are targeting Israeli-linked vessels in solidarity with Palestinians in Gaza.
According to sources from Hamas and Islamic Jihad, leaders from the two Palestinian Islamist groups, as well as the Marxist Popular Front for the Liberation of Palestine, held an "important meeting" with Houthi representatives last week.
The groups discussed "mechanisms to coordinate their actions of resistance" for the "next stage" of the war in Gaza, the sources said without identifying where the meeting took place.
The Palestinian groups and the Houthis also talked about a possible Israeli ground assault into southern Gaza's Rafah, said the sources, who requested anonymity.
According to the United Nations, around 1.5 million people are crowded into and around Rafah, Hamas's last stronghold in Gaza, most of whom are displaced and crammed against the Egyptian border in dire living conditions.
Israeli Prime Minister Benjamin Netanyahu's office said on Friday he had approved the military's plan for an operation in Rafah.
The Houthis confirmed they would continue their attacks on Red Sea shipping to "support the Palestinian resistance", according to the Hamas and Islamic Jihad sources.
The rebels' leader Abdul Malik Al Houthi said on Thursday their attacks would expand to target ships avoiding the Red Sea by navigating past South Africa's Cape of Good Hope.
Hamas's unprecedented October 7 attack resulted in about 1,160 deaths in Israel, mostly civilians, according to an AFP tally of official Israeli figures.
Israel's retaliatory campaign against Hamas has killed at least 31,490 people in Gaza, most of them women and children, according to the territory's health ministry.
Agence France-Presse