AFPTV footage from the scene showed a large crater gouged into the ground next to piles of rubble and twisted metal.

Surrounding buildings had their windows blown out and facades heavily damaged as emergency workers combed through the site.

Iranian state TV said a missile attack on the town in the Negev desert was a "response" to an earlier strike on its own nuclear site at Natanz.

The Israeli army said there was a "direct missile hit on a building" in Dimona and it was reviewing how the impact happened despite air defence interceptors being fired.

Magen David Adom first responders said their teams treated 33 people injured at a number of sites, including a 10-year-old boy with shrapnel wounds who was in serious condition but "fully conscious".

It said a woman of around 30 was in moderate condition, while 31 others were lightly injured by shrapnel or hurt on their way to shelters. Fourteen people were also treated for shock.

The organisation, Israel's equivalent of the Red Cross, released a video of a residential building ablaze in the town.

"There was extensive damage and chaos at the scene," paramedic Karmel Cohen said in a statement.

Israel's Prime Minister Benjamin Netanyahu released a message wishing "a speedy recovery to those injured as a result of the fire from Iran."

Images shared by Israeli media showed an object hurtling out of the sky at high speed before crashing into the town.

Israeli police released pictures of officers in a building with a large hole blown in the wall.

Israel has maintained a policy of ambiguity about its nuclear programme, and the Dimona plant officially focuses on research.

The casualties in Dimona came after Iranian authorities said the nuclear facility at Natanz in the Islamic republic was struck in the US-Israeli bombing campaign.

Israel's army had earlier told AFP that it was "not aware" of the strike on Natanz, suggesting it could have been carried out by the United States.

Iran has fired repeated barrages of missiles at Israel daily in retaliation for the US-Israeli attacks that started on February 28.