It is not a joke, nor a hoax, nor a sign of mental instability, nor an attempt to drum up local tourism by drawing the curious, the Soviet press agency Tass insisted today in discussions of what it called an extraterrestrial visit to southern Russia.
Residents of the city of Voronezh insisted today that lanky, three-eyed extraterrestrial creatures had indeed landed in a local park and gone for a stroll and that a seemingly fantastic report about the event carried Monday by the official press agency Tass was absolutely true.
''It was not an optical illusion,'' said Lieut. Sergei A. Matveyev of the Voronezh district police station, who said in a telephone interview that he saw the landing of the U.F.O. on Sept. 27.
Lieutenant Matveyev confessed that he had not actually seen the aliens, but said he saw the spaceship and ''it was certainly a body flying in the sky,'' moving noiselessly at a very high speed and very low altitude. 'Anything Is Possible'
To be honest, Lieutenant Matveyev said, he was a little skeptical himself when he first saw the object. ''I thought I must be really tired,'' he said. ''but I rubbed my eyes and it didn't go away. Then I figured, in this day and age, anything is possible.''
Using the sensationalist tone that has lately infected the once-staid Tass, the press agency today provided more details of the U.F.O. landing in Voronezh, a city some 300 miles southeast of Moscow.
According to Tass, and a report today in the newspaper Sovetskaya Kultura, two boys and a girl from a local school, Vasya Surin, Zhenya Blinov and Yuliya Sholokhova were playing in a park on the warm evening of Sept. 27 when suddenly, at half past six,
''They saw a pink shining in the sky and then spotted a ball of deep red color'' about 10 yards in diameter.
A crowd gathered, ''and they could clearly see a hatch opening in the lower part of the ball and a humanoid in the opening.'' A Stare Silences Boy
The three-eyed creature, about nine feet tall and fashionably dressed in silvery overalls and bronze boots and with a disk on its chest, disappeared, then landed and came out for a promenade with a companion and a robot.
The aliens seemed to communicate with each other, producing the mysterious appearance of a shining triangle, and activated the robot with a touch.
Terrified, a boy began to scream, but with a stare of the alien's shining eyes, Tass said, the boy was silenced and paralyzed.
After a brief disappearance, the three returned, but this time one of the ''humanoids'' had ''what looked like a gun'' by his side, a tube about two feet long that it directed at a 16-year-old boy. The boy, whose name was not given in the report, promptly vanished, but reappeared after the alien embarked in the ball.
Vladimir A. Moiseyev, director of the regional health department, said in a telephone interview that despite reports of widespread fear in the city, none of the witnesses had applied for medical help. But he said that ''certainly we are planning to examine the children.
'' There was no explanation why, with the passing of two weeks, such an examination had not yet taken place. Report Treated Seriously.
Mr. Moiseyev, like other authorities in Voronezh, the editors of Tass, and indeed many of its readers, treated the report as a serious scientific phenomenon.
No extra men are assigned to patrol the area because the department is short-handed, said the duty officer at the local Interior Ministry department, who identified himself only by his last name, Larin, but he said troops would be dispatched ''if they appear again.''