SAN FRANCISCO, Nov. 5 (Xinhua) -- U.S. social media network Facebook Inc. Monday removed 30 accounts from its namesake platform and 85 Instagram accounts for possible links to "foreign entities."

Nathaniel Gleicher, head of Cybersecurity Policy at Facebook, said U.S. law enforcement agencies notified Facebook Sunday evening about suspected online activities by those accounts with possible connections to foreign actors.

"We immediately blocked these accounts and are now investigating them in more detail," Gleicher announced Facebook's measures in an "Election Update" post, which came less than 12 hours before polls open for the U.S. midterm elections on Tuesday.

Gleicher said almost all the Facebook Pages associated with these accounts appear to be in the French or Russian languages, while those on Instagram seem to have mostly been English, with some focused on celebrities and others on political debates.

Instagram is a photo and video-sharing social networking service owned by Facebook.

"Once we know more -- including whether these accounts are linked to the Russia-based Internet Research Agency or other foreign entities -- we will update this post," he added.

Facebook said its probe of the activities is still at a very early stage, and it was unclear who were behind those attempts or how long those accounts have existed.

The Menlo Park, a California-based social media network, disclosed on Oct. 26 that it had pulled 82 Pages, Groups and accounts linked to Iran to crack down on online "bad actors."

With less than one day away from Tuesday's polling, social media companies are on high alert for foreign interference.

Major internet players such as Google, Apple and Twitter all have stepped up fight against online disinformation efforts, with hundreds of fake accounts purged from their platforms.