Their fears of a renegade Islamist attack on any of the top opposition leaders have been hiked by religious edicts issued by hardline clerics on TV saying they must be killed. But even before those edicts, activists have been worried by signs they say show that ruling Islamists are starting to target their ranks — disappearances of activists from protests, telephone death threats, warnings from security officials.

Some in the opposition say there’s no sure proof of a campaign, just worrisome patterns. But the fears point to how agitated the atmosphere has become in Egypt, with tempers hiked on both sides. The mainly liberal and secular opposition accuses Islamist President Mohammed Morsi of unleashing security forces to crush their protests against him. In turn, many Islamist backers of the president are convinced that the opposition is trying to topple a democratically elected leader by force…

Authorities appear to recognize the potential danger. The government increased security at the homes of Egypt’s top opposition figures, including Mohamed ElBaradei, a senior figure in the National Salvation Front. On Saturday, there was a startling moment when ElBaradei was getting into vehicle, tightly surrounded by bodyguards, and a middle aged man pushed toward him, shouting hysterically, “You’ll wreck Egypt, you’ll wreck Egypt” before guards pulled him aside.