"Three workers were killed and another three wounded," said Ramak Ramadan, district chief of Chamchamal where the Khor Mor complex is located.

He said that according to preliminary information, "the dead workers are foreigners".

Another source, who requested anonymity because he is not allowed to speak to the media, said two workers from Asia were killed and six wounded.

A drone hit the site at approximately 6.45 pm local time (1545 GMT) according to preliminary information, Ramadan said.

It "targeted a fuel storage tank", he added.

A security source confirmed the attack against the site which is owned by the United Arab Emirates firm Dana Gas.

There was no immediate claim of responsibility.

The gas field that came under attack lies between the cities of Kirkuk and Sulaimaniyah, in a region administered by Kurdish authorities.

Unclaimed Katyusha rocket attacks have targeted the same complex several times in recent years without causing significant damage.

In January, two Katyushas targeted the gas field, causing a blaze but no casualties.

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