Attorney General Janet Reno cautioned yesterday against reaching premature conclusions about the outcome of a U.S.-Mexican effort to excavate the remains of victims of drug-related violence buried on ranches in Ciudad Juarez, Mexico.

Mexican and U.S. law enforcement agents continued to dig at a ranch just south of Ciudad Juarez, on the Mexico-Texas border, but Mexican officials said no additional remains were found. Parts of skeletons and clothing from six bodies were unearthed Tuesday and Wednesday, officials said.

U.S. and Mexican authorities said this week that 100 or more bodies could be buried in a number of graves. Since then, law enforcement authorities have cautioned that the difficulty of removing and identifying the remains could take months.

While some skepticism has begun to build as the remains of only six people have been found in the past few days, Reno cautioned that it is too early to know what the sites will yield.

"I think it is important that the investigation and the processes take their course, so that we don't prematurely jump to conclusions and that we get to the truth and the heart of the matter," Reno said during her weekly media briefing.

Mexican and U.S. law enforcement agents have said the bodies are believed to be those of some of the nearly 200 Mexican and U.S. citizens who have disappeared from the Ciudad Juarez-El Paso border area in the past five years. Human rights organizations representing the victims' families have alleged that unscrupulous Mexican police and military authorities were involved in the crimes.

Correspondent Molly Moore in Ciudad Juarez, Mexico, contributed to this report.