By Jana Choukeir, Pesha Magid and Steven Scheer

DUBAI/JERUSALEM (Reuters) -An Israeli military official said on Thursday that "it was a mistake" for a military spokesperson to have said earlier in the day that Israel had struck the Bushehr nuclear site in Iran.

The official would only confirm that Israel had hit the Natanz, Isfahan and Arak nuclear sites in Iran.

Pressed further on Bushehr, the official said he could neither confirm or deny that Israel had struck the location, where Iran has a reactor.

The potential consequences of an attack on the plant -- contaminating the air and water -- have long been a concern in the Gulf states.

Qatar's prime minister, in March, warned that an attack on Iran's nuclear facilities would "entirely contaminate" the waters of the Gulf and threaten life in Qatar, the UAE and Kuwait.

Sheikh Mohammed bin Abdulrahman Al Thani warned that an attack on Iran's nuclear sites would leave the Gulf with "no water, no fish, nothing ... no life".

Qatar, the UAE and Kuwait, facing Iran on the opposite side of the Gulf, have minimal natural water reserves and are home to more than 18 million people whose only supply of potable water is desalinated water drawn from the Gulf.

Bushehr is Iran's only operating nuclear power plant, which sits on the Gulf coast, and uses Russian fuel that Russia then takes back when it is spent to reduce proliferation risk.

Russian President Vladimir Putin on Wednesday said that Moscow had agreed with Israeli leaders that the safety of Russian workers at the site would be guaranteed.

"Our specialists are on site. This is more than two hundred people. And we agreed with the leadership of Israel that their safety will be ensured," Putin told journalists.

The Russian embassy in Iran said in a statement earlier on Thursday that Bushehr was operating normally and that it did not see any security threats.

A source familiar with the matter told Reuters that contamination from any attack on Bushehr was the worst case Gulf countries were preparing for. The source stated that Gulf countries, in cooperation with the U.N. nuclear watchdog, had prepared a contingency plan for any attack on any nuclear plant in the region.

(Reporting by Jana Choukeir and Ahmed Elimam in Dubai; Pesha Magid in Riyadh and Steven Scheer in Jerusalem; Writing by Andrew Mills; Editing by Alison Williams, Aidan Lewis)