ORLANDO , Florida ( CNN ) -- The man accused of trying to sneak bomb-making materials on a flight from Orlando to Jamaica admitted he planned to build a bomb after he landed , according to an FBI agent . Witnesses say the man arrested Tuesday was `` rocking left and right and up and down . '' The man said he planned to `` detonate the device on a tree stump in Jamaica , but later told us he was going to show friends how to build explosive devices like the kind he saw in Iraq , '' FBI agent Kelly Boaz said in a court affidavit . The first court appearance for the man , Kevin Brown , was postponed Wednesday to allow government officials time to look into whether he suffers from mental illness . U.S. Army officials said Brown was in the service from September 1999 through December 2003 , when he received an honorable discharge . Although his record did not show a deployment to Iraq , he received an Army commendation medal in 2003 for serving in support of Operation Iraqi Freedom , officials said . His court-appointed attorney declined to comment . Brown , a Jamaican national , was arrested Tuesday on charges of `` carrying a weapon or explosive on an aircraft , '' the FBI said . He was taken into custody after an air safety officer noticed him acting strangely as he waited to board an Air Jamaica flight , federal authorities said . He appeared in court Wednesday but government officials asked for the delay , saying there were indications Brown might have a history of mental illness . A new hearing is scheduled for 3:30 p.m. Thursday . Transportation Safety Administration officials said a `` behavior identification officer '' noticed Brown acting strangely around noon Tuesday as he approached a ticket counter . Officials said Brown , who is believed to be in his early 30s , had checked baggage that contained two galvanized pipes , end caps , two containers of BBs , batteries , glass bottles containing nitromethane , a laptop , bomb-making literature and one model rocket igniter . Boaz , a member of law enforcement bomb squad , said the items could have been used to make bomb . `` The items found in Brown 's baggage constitute an incendiary device , '' Boaz said in court papers . `` The nitromethane was in a breakable container and the model rocket igniter would act as the wick . '' Initial record checks indicate Brown was in the United States legally , the FBI said . According to the bureau , he was living on the streets in Orlando , `` sleeping in the open . '' Federal investigators said he seems to have been living in several places , sometimes with relatives , and they do n't know his home town . `` It appears to be an isolated incident , but our investigation is continuing , '' the FBI 's David Couvertier told CNN . As part of the probe , officials are looking at whether Brown has ties to any organized group , he said . The FBI is being aided by Orlando police . Airport officials said several ticket counters were temporarily closed during the incident , and 11 flights were delayed . Airport spokeswoman Carolyn Fennell said Air Jamaica , Air Canada , West Jet and Frontier flights were among those delayed . E-mail to a friend . CNN National Correspondent Susan Candiotti and Rich Phillips contributed to this report .
NEW : Kevin Brown was honorably discharged from the Army . Brown admitted he planned to build a bomb after he landed , court documents say . FBI : Brown was arrested for carrying a weapon or explosives onto a plane . Brown tried to board flight at Orlando airport Tuesday .