A 28-year-old Pakistani man with explosives residue on his clothes was arrested at the U.S. Embassy in Chile, the State Department and Chilean national police said Tuesday.

U.S. Embassy officials in Santiago, Chile's capital, asked the man to come in for a routine consular issue and when he arrived, detectors registered the explosives residue, State Department spokesman P.J. Crowley said Tuesday afternoon at a briefing in Washington.

"We had information, we have information on this individual," Crowley said. " We ... brought him - invited him to come to the embassy to clarify the information that we had on this individual. And as he came into the embassy, our explosive detectors went off."

Crowley declined to give further details on why the man was asked to come in to the embassy.

A senior U.S. official told CNN the man was linked to an extremist group based in the Western Hemisphere and not to a group in Pakistan.

"As far as we can tell, the origin of the activities which brought him to our attention were more of a local or regional nature than international," the official said. "He came to Chile on a student visa and while there he associated himself with a group that we have some knowledge of that was espousing extremist and anti-Western views."

The official told CNN the man was on a watch list and was being tracked for some time because he was believed to be involved with the extremist group, which the official declined to identify. The official said the association was enough to call him to the U.S. embassy in Chile to revoke his visa. U.S. officials were surprised when he tested positive for TNT.

An investigation is underway to determine what he was doing with explosives and whether he posed a threat to the United States.

Crowley identified the suspect as Muhammad Saif-ur-Rehman Khan and said he was handed over to Chilean authorities. A spokesman for the Carabineros, Chile's national police, gave the man's name as Mauhamnas Saif Ur.

The explosives residue was found on the man's clothes, the Carabinero spokesman told CNN in a telephone interview from Santiago. He declined to give his name, following Carabinero policy.

The suspect was scheduled to have a court hearing Tuesday afternoon in which he would be charged with a firearms violation, the spokesman said.

Lt. Col. Fernando Vera of the Carabineros said in a televised interview that standard procedures were followed.

"The embassy has their security procedures in place and their security measures were activated, and that required the support of our personnel," Vera said. "Our personnel is on site and, according to agreements and protocols, the individual has been in custody of the interior minister."

The suspect had been in Chile since January and was doing an internship in tourism at a Chilean hotel, said CNN Chile, CNN's partner network in the nation.

Chilean authorities searched the man's apartment in a student housing district in central Santiago, CNN Chile reported. Video showed officials in white hazmat suits carrying items out of an apartment.

A neighbor said in a televised interview that the suspect was a religious man who went to a local mosque every day. Asked whether friends visited him, the unnamed neighbor said, "No. Nobody."

The incident occurred a week after Faisal Shahzad - a Pakistani-born naturalized U.S. citizen - was arrested in connection with a failed car bombing in New York's Times Square.