By Kristina Wong - 05/20/14 01:04 PM EDT
The U.S. is increasing the number of Marines and aircraft in Sicily that would evacuate Americans from the U.S. embassy in Tripoli, Libya, according to Reuters.
The Marines are part of a crisis response unit focused on embassy security created after the September 11, 2012, attack on the U.S. diplomatic compound in Benghazi, Libya, that killed four Americans, including U.S. Ambassador Christopher Stevens.
Fighting broke out in the Libya's capital over the weekend between political factions in the worst violence since the end of the 2011 uprising against Libyan dictator Muammar Gaddafi. Saudi Arabia closed its embassy and withdrew its staff on Monday.
Since Gaddafi's ouster, political fault lines have been forming between Islamist and liberal factions. Both sides are backed by heavily armed militias.
On Sunday, heavily armed fighters stormed the General National Congress building as members were evacuated, and fighting spread to other parts of the city. At least four people were killed and 90 injured, according to CNN.