The Associated Press
FILE - In this Wednesday, May 27, 2009 file photo, Ahmed Ali Saleh, the son of Yemeni President Ali Abdullah Saleh attends an event in Sanaa, Yemen. A Yemeni military official says the son of outgoing President Ali Abdullah Saleh is leading a crackdown within the powerful Republican Guard, which he commands, to purge it of rebellious officers. The official says Saleh's son, Ahmed, has had dozens arrested so far. He says the crackdown seeks to prevent officers from joining mass protests against Saleh's rule. (AP Photo, File)

SANAA, Yemen — Yemen's president now plans to remain in the country even after he steps down because protests that have spread to include employees of government agencies are threatening the rest of his regime, a senior member of the ruling party said Saturday.

President Ali Abdullah Saleh, who has ruled for 33 years, had said he would travel to the United States in an attempt to calm tensions in his country after 10 months of protests seeking his ouster. Saleh signed a deal last month to transfer power in exchange for immunity from prosecution over the deadly crackdown on protesters.

The deal, brokered by Yemen's neighbors on the Arabian Peninsula, has failed to end the unrest, however, because protesters in the streets want to see Saleh stand trial over the killings of hundreds of demonstrators. Instead, demonstrations have widened as employees stage sit-ins at government agencies and more members of the security forces rebel against commanders they accuse of corruption and playing a role in the crackdown.

"It is not possible in any way, shape or form to allow the collapse of state establishments and institutions that have been built over the last 49 years," Saleh said in a statement addressing the new threats.

He did not mention his plans to stay in Yemen, but Mohammed al-Shayekh, a leading member of Saleh's People's Congress Party, said separately that the president had decided to remain.

Meanwhile, the president's son, Ahmed, is leading a crackdown to purge the Republican Guard, which he commands, of any rebellious officers found to be siding with anti-government protesters, a military official said Saturday.

The Republican Guard is a pillar of Saleh's rule, and the attempts to ensure it remains loyal also point to an effort to keep the entire regime from unraveling in the wake of the deal for Saleh to transfer power.

Ahmed Saleh has had dozens of members of the powerful military force arrested so far, said the official, who spoke on condition of anonymity because of the sensitivity of the issue.

The Republican Guard has helped President Saleh maintain power despite the months of protests, intense international pressure and an assassination attempt in June that forced him to leave the country for weeks of medical treatment in neighboring Saudi Arabia.

The Guard, one of the best trained elements of Yemen's military, has not suffered a high number of defections like some other military units whose soldiers and commanders left to join the protest movement.

But with more frequent and serious acts of rebellion breaking out in other parts of the security services, the Guard's commanders are moving to prevent their ranks from doing the same.

The military official said Ahmed warned at a Guard meeting over the past week against "copying" the actions of others. They are searching units, barracks and have banned the use of cell phones inside the camp, the official said.

"We will not permit copying here. Force will be the way to deal with any protest," the official quoted Saleh's son as saying.

Some renegade units in other parts of the military have locked their commanders out of military installations and demanded the removal of officers accused of corruption or involvement in the deadly crackdown on protesters.

In a significant concession, the defense minister ordered the removal of a longtime Saleh confident within the armed forces, Ali al-Shater, known as one of the regime's strongmen. Protests by subordinates accused al-Shater of corruption and using his connections with the president to illegally amass wealth.

Another sweep in search of rebellious soldiers took place within the ranks of the Central Security forces, led by Saleh's nephew, Yahia, according to a Central Security official, who also spoke on condition of anonymity because of the secretive nature of the security measures.

Hundreds of men in military uniform marched on Saturday through the southern city of Taiz, a center of the uprising, calling for trials of top commanders over the killings of unarmed protesters in the regime's crackdown.

Also Saturday, hundreds of thousands of protesters held demonstrations in the capital city of Sanaa and in several other cities. They vowed to stop Saleh from leaving the country and to force him to stand trial.