Two citizens from Argentina with suspected links to Lebanon's Hezbollah were arrested on Thursday, leading up to the G20 summit due to take place in Buenos Aires at the end of the month, Argentina's security ministry said in a statement.
The two men, aged 23 and 25, were arrested in the capital, Buenos Aires. Police discovered a small arsenal that included a rifle, one shotgun and a number of pistols, among other weapons.
Police said they discovered evidence of travel abroad "along with credentials in Arabic and an image of the Hezbollah flag".
Police did not specify the nature of the travel or credentials, and did not say whether the men had intention of attacking the G20 event.
Security Minister Patricia Bullrich said on Thursday security forces were on the lookout for any suspicious activity ahead of the conference.
The Lebanese armed group along with Iran is suspected of having carried out the 1992 bombing of the Israeli embassy in Buenos Aires.
Argentine courts have blamed the attack on Iran but no one has been brought to trial in either that case or the 1994 bombing of a Buenos Aires Jewish centre that killed 85 people.
On Tuesday, the US State Department designated Jawad Nasrallah, son of Hezbollah leader Sayyed Hassan Nasrallah, a terrorist and accused him of carrying out attacks against Israel in the occupied West Bank.
"Today's designations seek to deny Nasrallah and AMB the resources to plan and carry out terrorist attacks," the State Department said in a statement then.
It said the actions denied Nasrallah and AMB access to the US financial system.