Mohabat News -- According to the Telegraph, written in English, Farsi, Arabic and Hebrew, the billboards carry the words "Thank You Iran" next to an image of the Iranian-made Fajr 5 rocket, which was fired at Israeli towns and cities, including Jerusalem Tel Aviv, during the eight-day war, which left 166 Palestinians and six Israelis dead.
The signs are certain to further fuel Israeli hostility to Iran's Islamic regime, which denies Israel's right to exist.
Their appearance at several major road junctions in Gaza follows boasts by senior Iranian officials that they had provided military assistance and "technology" to militant groups in the Palestinian territory.
Last week, the commander of Iran's Islamic Revolutionary Guard Corps, Major General Mohammad-Ali Jafari, said Iran had provided the "know-how" for Fajr 5 weapons to be produced in Gaza while the parliamentary speaker, Ali Larijani, said Tehran had given financial help.
It is not clear if the billboards, which are unsigned, were put up with the approval of Hamas, the Islamist organisation that runs Gaza.
The previous warm relations between Hamas and Iran have cooled recently because of Tehran's support for President Bashar al-Assad's regime in Syria against an armed uprising against his rule.
Khader Habib, a spokesman for Islamic Jihad, a smaller group with ties to Iran told Reuters it was natural to express gratitude to Iran.
"Iranian rockets struck at Tel Aviv. They reached out to Jerusalem. Therefore it was our duty to thank those who helped our people," he said.
But this week, Mousa Abu Marzouk, Hamas' deputy political director, warned Iran that it must reverse its policy on Syria if wanted to retain the support of Arab public opinion.
That prompted a critical commentary from the Iranian news website Tabnak, linked to the influential former Revolutionary Guard commander Mohsen Rezai, under the headline "Why Have the Leaders of Hamas Become Forgetful?".
The apparent fallout came just days after Khaled Mashaal, Hamas' leader-in-exile, and Ismail Haniyeh, the de facto prime minister of Gaza, publicly praised Iran's role in the recent conflict.