A pro-Syrian underground group, "The Eagles of the Revolution," claimed today that the top Jordanian diplomat they kidnaped in Beirut Friday has been taken to Syria and repeated a threat that he will be executed on Monday, a rightist Lebanese radio station said.

An alleged spokesman for the group called the station and claimed that Charge d'Affaires Hisham Moheisen has been moved to Damascus for treatment of "physical and psychological disorders," but another caller claiming to be a member of the same group said the envoy was being held in the Lebanese town of Laboue, about 50 miles northwest of Beirut.

The abduction, meanwhile, has increased the threat of an underground war between Syrian and Jordanian agents, Arab diplomatic sourses said today.

Jordan has openly accused Syrian military intelligence of kidnapping Moheisen.

Syria has dismissed the charge as part of what it calls a Jordanian campaign of hatred.

The diplomatic sources said the abduction has brought a simmering political conflict between the two erstwhile allies near the boiling point.

The sources said Jordan's leaders were convinced that Syrian agents were responsible for the kidnaping, and added that Amman could be considering reprisals unless Moheisen is released unharmed.