Two U.S. citizens are charged with scouting possible targets in New York and elsewhere for terrorist attacks by the Iranian-linked terrorist group Hezbollah, according to courts documents made public on Thursday.

Ali Kourani, 32, of New York, and Samer el Debek, 37, of Dearborn, Michigan, were arrested last week on weapons-related charges and multiple counts of providing material support for a terrorist organization and receiving military training from a terrorist organization, according to the documents, which were unsealed in U.S. District Court in Manhattan.

The FBI said in charging documents that no specific plot was underway but that Kourani and el Debek conducted extensive "pre-operational surveillance" to assess security vulnerabilities at the U.S. and Israeli embassies in Panama, as well as potential military and intelligence targets in New York.

Both men, who are naturalized U.S. citizens, appeared in court in the past week and could face life in prison if convicted, U.S. officials said.

Federal Court in Lower Manhattan on July 24, 2014 in New York. Stan Honda / AFP/Getty Images File

Kourani was born in Lebanon and legally entered the United States in 2003, prosecutors said. He is accused of conducting surveillance of potential military and intelligence targets in New York.

According to the FBI, Kourani — sometimes using the alias "Jacob Lewis" — began attending Hezbollah training programs when he was 16 and was a member of the Islamic Jihad Organization, which the U.S. government says is the name Hezbollah uses for its terrorist operations.

The documents do not say how or when el Debek entered the United States. He is accused of traveling to Panama to scout the U.S. and Israeli embassies and the Panama Canal for security vulnerabilities.

According to the FBI, el Debek joined Hezbollah in 2008 and frequently traveled to Lebanon on his U.S. passport for training in making bombs, something in which the court papers say he is "highly skilled." El Debek told investigators that one of his relatives carried out the 2012 bombing of a bus station in Burgas, Bulgaria, which killed six people and injured dozens of others, according to the court papers.

The United States has listed Hezbollah as a terrorist organization since the mid-1990s. An NBC News-Telemundo investigation in 2007 disclosed that the Iran-back militia has expanded operations with bases and extensive infrastructure across South America, from which members have easy access to the United States.