DUESSELDORF, Germany (Reuters) -German policymakers should team up with power grid operators to improve the response to incidents such as the arson attack near Tesla's gigafactory, said the head of regional utility Westenergie.

Security measures needed reviewing and a better legal framework created, Westenergie's chief executive Katherina Reiche told reporters in Duesseldorf.

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

But the response to deliberate and targeted actions by humans needs a rethink, she added.

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.

The outage at Gruenheide began on March 5, also affecting households in the region.

The Tesla plant was reconnected to the power grid late on Monday by eastern German grid operator E.dis, where personnel had worked in three-shift mode to ensure a quick restoration of supply.

Both Westenergie and E.dis belong to utility group E.ON.