Iranian missile strikes on two southern Israeli towns wounded more than 100 people on Saturday, medics said, after Israeli air defence systems failed to intercept the projectiles.

The two direct hits tore open the fronts of residential buildings and carved craters into the ground. 

Magen David Adom first responders said 84 people were wounded in the town of Arad, 10 of them seriously, hours after 33 were wounded in nearby Dimona. 

Iranian state TV said the missile attack on Dimona, which houses a nuclear facility, was a "response" to an earlier strike on its own nuclear site at Natanz. 

AFP footage from Arad showed rescue workers sifting through rubble for wounded people in a bombed-out building. 

Fire engines with their lights flashing were at the scene along with dozens of members of the emergency services. 

Firefighters said that in "both Dimona and Arad, interceptors were launched that failed to hit the threats, resulting in two direct hits by ballistic missiles with warheads weighing hundreds of kilograms".

The Israeli military said it would investigate the issue.

"The air defence systems operated but did not intercept the missile, we will investigate the incident and learn from it," military spokesman Brigadier General Effie Defrin wrote on X.

The local fire service said there was "extensive damage" in Arad, with three buildings affected and a blaze sparked in one of them.

The military's Home Front Command ordered schools in the area to move classes online.

Medic Riyad Abu Ajaj described "extensive destruction" at the site of the strike, in a statement from the organisation. 

"There was a lot of chaos at the scene," he said.

The rescue operations came not long after similar scenes in Dimona, around 25 kilometres (15 miles) to the southwest. 

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. 

Medics said they treated 33 people injured in the town, including a 10-year-old boy with shrapnel wounds who was in serious condition but conscious.

Dimona hosts a facility widely believed to possess the Middle East's sole nuclear arsenal, although Israel has never admitted possessing nuclear weapons. 

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

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

Israeli Prime Minister Benjamin Netanyahu vowed to continue striking Iran and its allies after what he called a "very difficult evening".