The boy and girl had stable vital signs Tuesday after undergoing hours of surgery, but no information was disclosed on whether doctors reattached their fingers.
A get-well banner hung at the South El Monte High School campus, and counselors consoled students after the horrific start Monday to the traditional Spirit Week celebrating homecoming.
Schools have conducted such games for years, El Monte Union High School District Superintendent Nick J. Salerno said.
"I've never heard of anything like this happening," he said. "It's unbelievable to me, it's shocking."
Officials will review all planned Spirit Week activities "that could even possibly have a risk of going wrong," Salerno said.
The district also plans to review policies to see if any need to be changed regarding tug-of-war games.
The teens lost four fingers each from their right hand, and the girl also lost the thumb on her left hand, Eddie Pickett, a supervising dispatcher with the Los Angeles County Fire Department, told NBC News.
However, sheriff's Sgt. Jorge Marchena told The Associated Press the girl lost three fingers on one hand and two on another, while the boy lost four fingers from one hand.
The discrepancy could not immediately be resolved.
"They're awake and alert," Los Angeles County-USC Medical Center spokeswoman Rosa Sacca said. "Parents are at their bedsides."
The girl is a senior and varsity soccer player, and the boy is a football player, the San Gabriel Valley Tribune reported.
The rope was wrapped around the students' hands, and it snapped, amputating their fingers, Pickett said.
"Our whole focus right now is providing support for the kids," Salerno said.
No criminal investigation will be done because the injuries were accidental, Marchena said.
"Somehow they got their hands tied up on the rope," he said.
Similar injuries have occurred elsewhere.
In 2008, an 8-year-old girl nearly lost four fingers when her hand got tangled in a rope during a tug-of-war in Fergus Falls, Minn. The fingers remained attached by tendons and were reattached.
In 2007, two students at a high school in Parker, Colo., had their right hands partially severed during a tug-of-war at a pep rally.
In 1997, two men had their left arms torn off when a rope snapped during a tug-of-war in Taiwan that involved some 1,600 participants. Doctors managed to reattach the limbs.