The siren went off on Tuesday night just as Netanyahu began his speech and addressed hundreds of supporters of the right-wing Likud-National Liberal Movement, which he chairs.
In an extraordinary scene captured on video from the event, the Israeli prime minister can be seen being whisked away from the stage by a gaggle of security guards.
“Leave quietly,” Netanyahu told the crowd before walking off the stage.
He returned some 20 minutes later to resume his speech.
“If Hamas is shooting at us in a live broadcast, you can understand they don’t want us here,” Netanyahu told Likud supporters. “So prepare for another one. We’ll evacuate, and then we’ll return.”
In nearby Ashkelon, member of Blue and White political alliance and former Chief of General Staff of the Israeli military forces, Gabi Ashkenazi, had to cut a campaign event short due to the rocket fire.
The Israeli military said at least two rockets were shot at the occupied territories, claiming that both projectiles were intercepted by the so-called Iron Dome missile system.
Israeli medics said a 46-year-old woman was treated in Ashdod for anxiety after failing to reach shelter, but no other injuries or damage were reported.
Leader of the hard-line Yisrael Beiteinu party Avigdor Lieberman was evacuated from a party event at a restaurant in Ashdod.
Lieberman, a former Netanyahu ally turned nemesis, said the incident “proves that Netanyahu’s policies … are bankrupt. We must change direction.”
Earlier in the day, Netanyahu announced his intention to annex the Jordan Valley in the occupied West Bank if he wins the September 17 polls.