Four men were arrested on charges of plotting to kill Americans overseas and bombing public buildings by engaging in jihad, FBI officials said Monday.

The arrested men are Sohiel Omar Kabir, 34; Ralph Deleon, 23, of Ontario, California; Miguel Alejandro Santana Vidriales, 21, of Upland; and Arifeen David Gojali, 21, of Riverside.

The men are accused of joining terrorist group al-Qaeda to kill Americans, plotting to bomb government and public facilities and offering to provide material support to terrorists to carry out attacks.

“The defendants conspired to provide material support to terrorists in preparation for or in carrying out: conspiracy to kill, kidnap, maim, or injure persons and damage property in a foreign country, killing and attempting to kill officers and employees of the United States, killing nationals of the United States, conspiracy to use a weapon of mass destruction outside the United States; and bombing places of public use and government facilities,” FBI said in a criminal complaint filed in a district court in California.

Kabir, a naturalized U.S. citizen born in Afghanistan, had links with terrorist groups such as Taliban and al-Qaeda and had travelled to Afghanistan, Reuters reported quoting the FBI. According to the complaint, he introduced Deleon and Santana to the violent jihad by providing them with the several doctrines and extremist reading material.

He had also made travel arrangements for Deleon and Santana to travel to Afghanistan and to connect them with the terrorist groups to get trained.

According to the complaint, Kabir said that “he would wait for their arrival before departing to a training location in Afghanistan and that, when they arrived, they would meet the students and the professors,” KTLA reported.

The students and professors here were codenames for Taliban and al-Qaeda respectively, the complaint said.

The plot was unraveled when Deleon and Santana told a confidential source in the FBI that they would be travelling to Afghanistan to engage in jihad and even discussed the roles they would prefer to play in an armed combat.

Deleon wanted work on the frontlines in case of a combat, or handle explosives, while Santana said he wanted to become a sniper and added that he had experience with firearms.

Deleon and Santana later recruited Gojali, a U.S. citizen, and made plans to join Kabir in Afghanistan and raised funds for the travel. According to the complaint, the trio also conducted a training camp, wherein they trained at firearms and paintball facilities as a preparation for terrorist training overseas.

The defendants were arrested Friday and, if convicted, face a maximum penalty of 15 years in federal prison.