FILE PHOTO: People holding mobile phones are silhouetted against a backdrop projected with the Twitter logo in this illustration picture taken in Warsaw September 27, 2013. REUTERS/Kacper Pempel/File Photo

(Reuters) - Twitter Inc said on Wednesday it had expanded notifications to about 1.4 million people, who were exposed to content generated by a suspected Russian propaganda service.

The company had said earlier this month it would email 677,775 people in the United States who followed, retweeted or liked content from accounts associated with the Internet Research Agency (IRA) during the election.

The IRA is a Russian organization that according to lawmakers and researchers, employs hundreds of people to push pro-Kremlin content under phony social media accounts.

The company said it would not notify every person who saw the content and would instead focus its efforts on certain types of interactions.

Two senior Democratic lawmakers had asked Facebook Inc and Twitter to answer questions about potential Russian involvement in social media campaigns.