A suburban Dallas man was arrested Thursday after FBI agents accused him of lying to them about whether he supported the leader of the Islamic State group.

Bilal Abood, 37, of Mesquite, admitted he posted an oath on Twitter to Abu Bakr al-Baghdadi, the leader of the Islamic State, according to a criminal complaint. The complaint further states that agents searching Abood's computer also found he was watching beheadings carried out by Islamic State fighters.

The Islamic State rules parts of Iraq and Syria and has taken responsibility for attacks including a shooting earlier this month outside a controversial Prophet Muhammad cartoon contest in Garland.

Abood is being held in federal custody pending a detention hearing before a judge in Dallas on Friday. He did not have an attorney listed in online court records who could comment on the allegations.

According to court documents, Abood is a naturalized U.S citizen who immigrated to the United States from Iraq in 2009.

On March 29, 2013, Abood was blocked from boarding a flight from Dallas-Fort Worth International Airport, the complaint states. When FBI agents at the airport asked him about his travel plans, he initially said he was flying to Iraq to visit family. In a subsequent interview, when he was asked specifically if he intended to go to Syria to fight, he denied that was his intent. Later in the interview, though, he admitted that his plan was to travel to Syria to fight against the Assad regime, saying he wanted to fight with the rebel Free Syrian Army.

About a month later, Abood left the U.S. through Mexico and traveled through various countries to reach Turkey, according to the complaint. When he returned to the U.S. that September, the FBI questioned him and he said he had traveled through Turkey and stayed in a Free Syrian Army camp. He said he decided to return to the United States after becoming frustrated by a lack of action. He denied ever providing financial support to the Islamic State or any other terrorist organization.

However, an examination of Abood's computer in July 2014, showed he had pledged an oath to al-Baghdadi the previous June.

When FBI agents returned his computer in April, Abood again denied that he had ever pledged allegiance to al-Baghdadi.

Lying to federal agents is punishable by up to eight years in prison and a fine of up to $250,000.