One of the assailants was armed with an assault rifle and the other with a knife.
The forum of relatives of the kidnapped persons had called for rallies and a day of fasting to mark the 500 days under the slogan “Get them out of hell.”
Yemeni movement Ansar Allah, also known as the Houthis, said it had struck the Israeli Defence Ministry in Tel Aviv with a hypersonic missile.
With a ceasefire holding by a thread, this was an inauspicious time to visit anywhere in the area, let alone the country at the heart of the renewed conflict.
The Israeli military, in posts on Telegram, said most projectiles were intercepted, but one came down in an open area in central Israel.
The attack was said to have been a response to the killing of Hezbollah leader Hassan Nasrallah and others.
Mr Netanyahu warned Iran against an attack on Israel.
Warning sirens rang out across Tel Aviv in the early hours of Friday as air defence intercepted a missile fired from Yemen, the Israeli military said.
Israel claimed that Hamas is still holding 101 people.
Chief Rabbi Ephraim Mirvis expressed disbelief at the decision, citing the recent murder of six hostages by terrorists.
