SANAA - Protesters planned massive "Day of Departure" demonstrations against veteran President Ali Abdullah Saleh in Yemen on Friday and Amnesty International warned he could not just shoot his way out of the crisis. Western countries are alarmed that al Qaeda militants entrenched in the Arabian Peninsula state could exploit any disorder arising from a messy transition of power if Saleh, an important US and Saudi ally fighting for his political life, finally leaves office after 32 years. Protesters who have been encamped in their thousands outside Sanaa University for six weeks declared Friday a "Day of Departure" when they hoped to bring hundreds of thousands onto the streets of the capital Sanaa once more in an attempt to oust the perennial political survivor. Similar mass protests last Friday left 52 people dead, apparently at the hands of plainclothes snipers. That bloodshed prompted a string of generals, diplomats and tribal leaders to abandon Saleh and severely weaken his position. "The government cannot just shoot its way out of this crisis," Philip Luther, Amnesty's Deputy Director for the Middle East and North Africa, said in a statement. "Whether in uniform or in plainclothes, security forces must be immediately stopped from using live ammunition on unarmed protesters." Saleh's supporters in Sanaa were out early on the streets of a tense capital in an effort to challenge the protests planned for after Friday prayers. Some were riding motorbikes with large posters of Saleh affixed to them, waving flags and playing patriotic music. "No to chaos, yes to security and stability," their banners said. Saleh, who oversaw the 1990 unification of north and south Yemen and emerged victorious from a civil war four years later, has shown no signs publicly of being prepared to stand down. He has offered a string of concessions, all rejected by opposition parties, including this week to hold presidential elections by January 2012. He has also warned military officers who have turned against him not to plot a coup. The Wall Street Journal reported on Thursday that Saleh and top general Ali Mohsen -- the most significant of this week's defectors �" were hashing out a deal whereby both men resign within days to allow a civilian transitional government. But Saleh was defiant in a speech on Thursday, offering only an amnesty to defecting troops at a meeting with commanders. Mohsen, widely seen as Yemen's second most powerful man, told Reuters on Thursday he had no presidential ambitions himself. An Islamist and kinsman of Saleh, Mohsen is seen by many Yemenis as part of the system they want to change. Army units have clashed twice this week with presidential guards headed by Saleh's son Ahmed in the southern town of Mukalla on the Arabian Sea. Saleh also has the intelligence services, run by close allies, on this side.