DUESSELDORF, Germany (Reuters) - German policymakers should come on board with grid operators to step up responses to incidents such as the arson attack near Tesla's gigafactory near Berlin, said the head of Germany's Westenergie, parent to a weighty grid firm.

Security measures needed reviewing and a better legal framework created, Chief Executive Katherina Reiche told reporters in Duesseldorf.

"Critical infrastructure is vulnerable," said Reiche, whose subsidiary Westnetz dealt with restoring tens of thousands of households in western Germany with power after flooding in 2021.

But a rethink was necessary over what to do against deliberate and targeted actions by humans.

In the Tesla case, far-left activities from the Vulkangruppe claimed responsibility for the attack that caused a week-long outage at its Gruenheide factory in the state of Brandenburg.

"It is probably not possible to protect such a network to a 100% degree at all times," Reiche said, adding that gas and telecommunications intersections were also exposed to attacks.

Transparency rules requiring grid operators to make their infrastructure data publicly available might be in need of review, she said, as they could potentially identify and provide pointers to where to find targets.

Westenergie belongs to utility group E.ON.

(Reporting by Tom Kaeckenhoff, writing by Vera Eckert, editing by Madeline Chambers)