Iranian rocket specialists are in the Gaza Strip, helping terrorist organizations develop their arsenal of projectiles, Palestinian security officials said Tuesday, hours after a rocket was fired at Israel for the first time in months.

Representatives of the Iranian Revolutionary Guard were helping Hamas, which rules the Strip, and the Islamic Jihad organization develop long-range rockets, the Hebrew news site Walla reported, citing the unnamed Palestinian officials. Israeli officials confirmed there was an Iranian presence in Gaza, adding it wasn’t the first time Iranian officials had entered the Strip, the report said.

The report could not be confirmed independently.

On Thursday morning, an upgraded Fajr missile, with a range of 70 kilometers (over 40 miles), landed south of Ashkelon, breaking a truce between Israel and the terror groups in the Strip which had held since the end of Operation Pillar of Defense in November. In response to the rocket fire Tuesday, Israel temporarily curtailed operations at two Gaza border crossings.

Fatah’s military wing claimed responsibility for the attack, but Israeli reports said it was likely that Hamas — which controls Gaza — was also involved at some level.

In November, a senior Hamas official predicted that Iran would increase its military and economic aid to Gazan groups because of the victory his group claimed in Pillar of Defense, the eight-day confrontation with Israel.

“They give it to us in the name of Allah, without conditions, and I am a witness to this,” Mahmoud al-Zahar told reporters in Gaza at the time, adding, “It is our right to take money and weapons from Iran.”

Ilan Ben Zion contributed to this report.