A jailed gang member poses for a photograph at the maximum security jail of Izalco in Sonsonate, El Salvador, March 5, 2013. Reuters

The Los Angeles police arrested 21 members and associates of infamous street gang Mara Salvatrucha, or MS-13, early morning Wednesday. In what is said to be the largest ever crackdown on the gang in Los Angeles, hundreds of federal and local law enforcement officers spread out across the city to serve arrests and search warrants, Reuters reported.

The exercise was a part of a three-year investigation into the ultraviolent street gang, which was started by immigrants from El Salvador in the 1980s, Reuters reported citing officials.

It is estimated that the gang has more than 10,000 members in the U.S. alone and over 30,000 worldwide, according to Fox News.

Read: Trump Blames Obama For Rise Of MS-13 Gang In Recent Years

The Los Angeles raids focused on nabbing members of MS-13's core leadership, the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) told CNN. "Today we disrupted this gang's command and control," said Eric Harden, special agent in charge of the ATF's Los Angeles field division.

Some of the MS-13 gang members have been deported from the U.S. in the past several years, which is likely the reason for expansion of this group in other nations. New York Daily News cited a FBI report of 2009 which said MS-13 had around 30,000 to 50,000 members (internationally).

According to the website of Federal Bureau of Investigation (FBI), MS-13 and another gang named 18th Street, continue to expand their influence in the U.S. FBI investigations suggest that these transnational gangs exist in almost every state. These gangs are focusing to grow their membership and mostly targeting younger recruits to join them.

MS-13 is active in 40 states in the U.S. and the District of Columbia. The gang has a unique way of welcoming their new members. They force new members to endure a 13-second beating known as "jumping in," Los Angeles authorities told CNN. Existing members beat the new members with fists and bats in videotaped beatings often lasting far longer than 13 seconds. New women members either jump in or are "sexed in," having sexual relations with MS-13 members.

The Los Angeles authorities have a long history fighting the MS-13 gang; however, the gang has found a recent spotlight under the administration of President Donald Trump. The current administration is clear on strengthening its border security and immigration enforcement. The administration, however, has failed to give the media data on how many MS-13 members are believed to be in the U.S. illegally, CNN reported.

Just this week, at the 36th Annual National Peace Officers' Memorial Service, Trump said that how freedom in the nation also refers to freedom from crime and violence. He said: "MS-13 is going to be gone from our streets very soon, believe me."

On April 23, Trump had tweeted mocking the Democrats, saying that they are still against building the U.S.-Mexico border wall despite knowing that the wall will stop flow of drugs into U.S. and MS-13 gang members.