Facebook has blocked 115 accounts for suspected “coordinated inauthentic behaviour” on the eve of the US midterms.

The social media company said in a blog post it shut down 30 Facebook accounts and 85 Instagram accounts and is investigating them in more detail.

The company said it took action after being tipped off on Sunday evening by US law enforcement officials, “which they believe may be linked to foreign entities”, Facebook’s head of cybersecurity policy, Nathaniel Gleicher, wrote in the post.

US midterm elections: the voters Show all 10 1 /10 US midterm elections: the voters US midterm elections: the voters Ross Kershey of Exton, Pennsylvania objects to President Trump's recent threat to unilaterally suspend the constitutional protection of birthright citizenship as a way to control undocumented immigrants AP US midterm elections: the voters Thomas Jakel of Eveleth Minnesota is a former miner. The economy is the most important thing to voters in his town AFP/Getty US midterm elections: the voters Jerry Mcneff of Exton, Pennsylvania intends to split his ballot between the parties for Pennsylvania's House, Senate and governor elections AP US midterm elections: the voters Jean Hoffman of Exton, Pennsylvania has concerns about the cost of her daughters' college education. She thinks that voting Republican might help extend the economy's rise AP US midterm elections: the voters Supporters attend a rally of President Trump in Rochester, Minnesota AFP/Getty US midterm elections: the voters Supporters attend a rally of President Trump in Rochester, Minnesota Reuters US midterm elections: the voters Supporter Jenny Haley and son wait in line to see a Trump Rally in Rochester, Minnesota AFP/Getty US midterm elections: the voters Dick Calef of Exton, Pennsylvania is a life-long Republican. He credits the economic gains in suburban Philadelphia to longer-term factors beyond Trump's policies, such as the growth of internet and health care companies. He's not yet sure how he will vote AP US midterm elections: the voters Markus Fasel of Mendota Heights, Minnesota attends a campaign event for Democrat Angie Craig, his favoured congressional candidate AFP/Getty US midterm elections: the voters Supporters attend a rally of President Trump in Rochester, Minnesota Reuters

“Almost all the Facebook Pages associated with these accounts appear to be in the French or Russian languages,” Facebook said.

The internet giant said the Instagram accounts “seem to have mostly been in English – some were focused on celebrities, others political debate”.

Facebook said once it learns more it will provide further updates, “including whether these accounts are linked to the Russia-based Internet Research Agency or other foreign entities”.

Tech companies in the US are stepping up security and efforts to fight disinformation campaigns as online troublemakers including Russian groups attempt to divide voters and discredit democracy.

Last month, Facebook removed 82 pages, accounts and groups tied to Iran aimed at stirring up social strife in the US and the UK.