MOSCOW — Several Russians arrested last week in Texas and accused of illegally exporting microelectronics to Russian military and intelligence agencies have been subjected to “psychological and moral pressure” to make admissions of guilt, the Russian Foreign Ministry said Friday in a statement.

The ministry did not say what it believed was done to the Russians, who are in federal prison in Texas.

The F.B.I. said the members of the group, including electrical engineers who have lived for years in the United States, posed as traffic-light manufacturers to obtain microprocessors and memory chips sold openly in the United States but requiring a license to export, lest they wind up in military equipment. Some chips later wound up in Russian weaponry like MIG fighter jets, the agency said.

The Russians were detained on Oct. 3. The statement issued Friday in Moscow said a judge in Houston had denied pretrial release on “made-up pretexts.” It said Russian diplomats would support the defense lawyers’ appeal of the judge’s ruling.