Wave of detentions is unprecedented in the Central American country that has suffered decades of violent crime driven by powerful gangs such as Mara Salvatrucha and Barrio 18.
El Salvador President Nayib Bukele has said that the Central American country has arrested more than 10,000 suspected gang members as part of a recent push to drive down violent crime.
"10,094 terrorists arrested in 17 days. We're continuing the War Against Gangs," Bukele wrote on Twitter on Tuesday.
Bukele announced a state of emergency at the end of March following a bloody weekend in which 87 people were killed in gang-related violence.
Since then, police and the military have rounded up thousands of suspected gang members using emergency powers allowing them to do so without arrest warrants.
On Monday alone, police arrested 463 suspected gang members.
The wave of detentions is unprecedented in a country that has suffered decades of violent crime driven by powerful gangs such as Mara Salvatrucha (MS-13) and Barrio 18.
These gangs count on around 70,000 members, some 26,000 of whom are currently in jail, according to authorities.
Bukele hit out at US
On Monday, Bukele hit out at the administration of US President Joe Biden over a perceived lack of support.
It came after US State Department spokesman Ned Price tweeted that "the US government continues to support El Salvador in its efforts to reduce the proliferation of gangs.
"We urge El Salvador to protect its citizens while also upholding civil liberties, including freedom of the press."
That sparked a furious response from Bukele who said that support had come from Biden's predecessor Donald Trump.
"You are only supporting the gangs and their 'civil liberties' now," said Bukele.
The government has enacted various legal reforms this month, including quintupling prison sentences for gang membership.
On Sunday, US Secretary of State Antony Blinken said Washington had "invested $411 million to improve citizen security and help the Salvadoran government combat gang violence" since 2008.