Norway will deploy its military to protect its oil and gas installations against possible sabotage after several countries said two Russian pipelines to Europe spewing gas into the Baltic had been attacked, the prime minister said on Wednesday.

Gas leaks as a result of suspected sabotage discovered on the Nord Stream pipelines on Tuesday have roiled energy markets and heightened security concerns.

Norway is now Europe's largest gas supplier and a leading global oil supplier. It has over 90 offshore oil and gas fields, most of which are connected to a network of gas pipelines stretching some 9,000 km.

"The military will be more visible at Norwegian oil and gas installations," Prime Minister Jonas Gahr Stoere told a news conference.

Any attack would be "handled jointly with our allies," he said. Norway is a NATO member.

At sea, the Navy would be deployed to protect offshore installations, while on land, police could increase presence at facilities, he said.

NATO and the European Union have stressed the need to protect critical infrastructure and warned of a "robust and united response" should more attacks occur.

On Monday, Norway's Petroleum Safety Authority urged greater vigilance over unidentified drones seen flying near Norwegian offshore oil and gas platforms, warning they could pose a risk of accidents or deliberate attacks.

Stoere said on Wednesday the drone sightings took place "mainly in September," involved drones of "various sizes" and that the activity was "abnormal."

Still, he reiterated he saw no specific threat against Norway's offshore oil and gas sector and had not asked for military assistance from its allies.

Equinor, Europe's largest gas supplier, said on Wednesday it had stepped up security measures at its installations.

The Norwegian military was keeping a "vigilant eye" on the situation, said a spokesperson for the Norwegian Joint Headquarters, the military's operational command center.

(Source: Reuters with edits)