Blasts reported around Tehran after a year of escalating confrontations.

Several explosions were reported in Iran early on Saturday, raising fears that a long-brewing confrontation between Israel and Iran, two of the most powerful militaries in the Middle East, could escalate into an all-out war.

Fars and Tasnim, both news agencies run by the Islamic Revolutionary Guards Corps, reported that several blasts were heard in Tehran, but gave no further details.

The blasts, more than 1,000 miles from Israel, came 26 daysafter Iran fired several waves of ballistic missiles at Israel, forcing millions of Israelis to take cover in bomb shelters, and damaging several homes and air bases.

The Israeli military did not immediately comment.

The blasts followed a year of rising confrontation between Israel, Iran and its proxies, in the shadow of the war in Gaza.

For years, Israel and Iran have fought a clandestine war in which both sides attacked each other’s interests and allies, while rarely acknowledging involvement. That conflict turned into an open confrontation earlier this year, as the war between Israel and Hamas, Iran’s ally in Gaza, began to involve Iran more directly.

Iran first fired ballistic missiles at Israel in April after Israeli fighter jets killed several senior Iranian commanders as they visited Syria.

Earlier this month, Iran fired more ballistic missiles at Israel in response to Israel’s killing of Hassan Nasrallah, the longtime leader of Hezbollah, another ally of Iran; Ismail Haniyeh, the chairman of Hamas’s political office, who was visiting Iran at the time of his assassination; and a senior official in the Iranian Revolutionary Guards Corps. Israeli air defenses intercepted many of the Iranian missiles, which killed a Palestinian in the Israeli-occupied West Bank but no Israelis.

Israeli leaders vowed to respond with their own attack, which had been expected this weekend.