Authorities say Khalid Ali-M Aldawsari, 20, had been researching online how to construct an explosive device using several chemicals as ingredients. He was allegedly planning to those put bombs inside dolls and baby carriages.
Aldawsari was arrested Wednesday at his home in Lubbock, Tx. He was expected to appear in federal court on Friday after being charged with attempted use of a weapon of mass destruction.
The FBI said Aldawsari was in the U.S. legally on a student visa. He moved to the U.S. in October 2008 from Saudi Arabia to study chemical engineering at Texas Tech University, then transferred earlier this year to nearby South Plains College.
According to authorities, Aldawsari tried several times to buy phenol, a chemical that can be used to make an explosive, on Feb. 1 from a North Carolina company, Carolina Biological Supply. He told the company he was using the chemical for personal research.
But the company asked him too many questions, so he reportedly abandoned his purchase and instead emailed himself instructions on how to produce the chemical at home.
The company reported Aldawsari to the FBI, and within weeks, federal agents had traced his other online purchases, discovered extremist posts he made on the Internet and secretly searched his apartment, computer and e-mail accounts and read his diary, according to court records.
"It is war ... until the infidels leave defeated," Aldawsari wrote in online postings.
In e-mails he apparently sent himself, he listed the names of 12 reservoir dams in Colorado and California. He also wrote an e-mail that mentioned "Tyrant's House" with the address of President Bush's home.
Federal authorities say Aldawsari also indicated in his diary that he had been planning an attack for years and that he obtained a scholarship just so he could come to the U.S. to carry out jihad.
In response to the arrest, the FBI sent out a flyer to businesses across the country as a reminder to watch out for anyone who might be planning a terrorist attack using fertilizer, chemicals or pesticide-based explosives. They also warned farm supply stores to be aware of anyone who might be acting in a way that could indicate potential terrorist activity.
The Associated Press contributed to this story.