MARS, Pa. (AP) _ Soviet cosmonaut Sergei Krikalev landed in Mars Wednesday and was greeted by hundreds of young star-struck Martians waving crayon drawings and homemade Soviet and American flags.

''Welckim To Mars,'' one first-grader wrote on a note accompanying a rocket ship made of purple construction paper.

Krikalev, 31, a flight engineer who lives near Moscow, visited 367 kindergarten through second-grade students at the Mars Primary Center. He was joined later Wednesday by U.S. astronaut Mario Runco Jr., 37, a Navy lieutenant commander awaiting assignment to his first shuttle mission.

''Hopefully this is one small step, if you will, for some future cooperation'' between the two nations, Runco told reporters after he gave the school 485 NASA photographs.

The Soviet spaceman said he was touched by the students' gifts, which included letters, T-shirts, fresh-cut flowers, Russian tea cakes and crayon and watercolor renderings of their vision of outer space.

''It's not so much the gifts. It's the friendliness that went behind the gifts. It's coming from the insides of the people who gave the gifts,'' he said.

Krikalev passed out photographs showing himself and his two partners during a five-month French-Soviet Soyuz mission that ended in April.

The cosmonaut, in Mars for an eight-day visit, and Runco were invited to this small community 25 miles north of Pittsburgh by the Mars Area Foundation for Educational Excellence. Both men also visited the community's Adams Intermediate Elementary School for grades two through five.

Each man put on a rubber boot and stepped into a tray of brown clay, then signed his name in the clay. The footprints and signatures were sealed in glass and marked with a plaque noting that both men ''stepped on Mars, Sept. 27, 1989.''

''The goal was to bring unusual cultural programs to the school district, and it has blossomed beyond anything I had imagined,'' said Ralph Terrell, foundation chairman.

''What I really want to promote is for the kids to study hard, and in the future to get along with the other country,'' Krikalev said through an interpreter.

Krikalev fielded questions from the students during a morning assembly, then visited classrooms. One student asked whether he worries about accidents like the explosion of the space shuttle Challenger.

''No. We all have our jobs to do,'' said Krikalev, whose gray suit sported a lapel pin depicting the U.S. and Soviet flags.

Other students asked what it's like to sleep, eat and float in space.

''I answer the same questions from our children,'' he said with a smile.

The school's hallways were decorated with the children's space drawings. A flying saucer, 10 feet in diameter and made of steel barrel lids, adorned the town center.

Krikalev said his Soviet friends were surprised to hear of a town named Mars, and an American acquaintance in Moscow had never heard of it.

''I couldn't find Mars on the map,'' he said. ''I didn't know what kind of clothes to bring, because I didn't know where it was.''

The teachers and the children's parents seemed almost as excited as the children by the visit.

''It's almost like putting Mars on the map. This Mars, not the planet,'' said Minette Thompson, a fifth-grade teacher.