Facebook and Twitter logos are seen on a shop window in Malaga, Spain, June 4, 2018. (Xinhua/REUTERS)

SAN FRANCISCO, Aug. 21 (Xinhua) -- Social media giants Facebook and Twitter announced Tuesday they were removing accounts, groups and pages suspected of spreading fake news, with some of them sponsored by foreign agencies.

Facebook said it removed 652 fake accounts. Some of these displayed "coordinated inauthentic behavior that originated in Iran and targeted people across multiple internet services in the Middle East, Latin America, UK and U.S.," it said.

The U.S. tech giant received a tip in July from cybersecurity firm FireEye about Liberty Front Press, which describes itself as a network of independent media organizations.

An investigation found the network was linked to Iranian state media and one component, Quest 4 Truth, had ties with Press TV, an English-language news network affiliated with Iranian state media, Facebook said.

It noted that the Iranian media increased posting contents about Britain and the U.S. from 2017.

Facebook said it is cooperating with U.S. law enforcement authorities to continue the probe into these activities.

This is the second time in less than a month that Facebook announced it was removing some foreign-sponsored accounts for "coordinated inauthentic behavior" across its platforms, including its photo-sharing service Instagram.

Only July 31, Facebook said it deleted 32 pages and accounts that aimed to exert political influence through fake information ahead of the upcoming U.S. mid-term elections.

Twitter also announced it has taken down accounts originating from Iran.

"Working with our industry peers today, we have suspended 284 accounts from Twitter for engaging in coordinated manipulation. Based on our existing analysis, it appears many of these accounts originated from Iran," Twitter said in a post Tuesday.

It also said it is engaging with other companies and law enforcement units to proceed with investigations into fake accounts.

U.S. social media networks have been under heavy scrutiny recently as federal regulators are concerned about "media manipulation" by foreign countries ahead of the U.S. midterm elections.

There is growing tension between the U.S. and Iran after Washington announced on Aug. 6 it would reimpose the economic sanctions against Tehran that were lifted under a 2015 nuclear accord.

The sanctions follow U.S. President Donald Trump's decision in May to withdraw from the Iran nuclear deal reached between Tehran and the five UN Security Council members plus Germany and the European Union.