TEHRAN: Iran warned of "severe consequences" as the deadly conflict between Israel and Hamas resumed on Friday after a seven-day truce expired.

Militants from the Iran-backed Hamas launched an unprecedented attack on southern Israel on October 7 in which Israeli officials say about 1,200 people were killed, mostly civilians, and around 240 were taken hostage.

Israel, whose main ally is the United States, vowed to destroy Hamas in response and unleashed an offensive that Gaza's Hamas government says has killed more than 15,000 people in the Palestinian territory, mostly civilians.

Fighting resumed on Friday after the expiry of the temporary truce that saw Hamas release 80 Israeli hostages in exchange for 240 Palestinian prisoners.

"The continuation of the Washington and Tel Aviv war means a new genocide in Gaza and the West Bank," Iran's Foreign Minister Hossein Amir-Abdollahian said Friday in a post on X, formerly Twitter.

"It appears that they do not think about the severe consequences of returning to war," he added.

Israel accused Hamas of breaking the pause by attempting to launch a rocket attack shortly before it was due to come to an end Friday at 0500 GMT.

A source close to Hamas told AFP the group's armed wing had received "the order to resume combat" and to "defend the Gaza Strip."

The health ministry in the Hamas-run Palestinian territory said at least 60 people had been killed in the hours after the truce ended.

Iran's foreign ministry spokesman Nasser Kanani had earlier blamed Israel and the United States over the resumption of hostilities.

In a post on X, Kanani said "the political and legal responsibility for the continuation of the aggression and massacre" rested with Israel, the United States and "governments that support this apartheid regime".

US Secretary of State Antony Blinken, who met Thursday with Israeli and Palestinian officials, called for a truce extension and said Palestinian civilians must be protected if hostilities resume. Other world figures had also appealed for a longer pause.

"The nations and the vast majority of the governments of the world are shouting for the continuation of the ceasefire and the complete stop to the Zionist regime's attacks against Gaza and the West Bank," Kanani said.