Party representatives inside the Houthi-run Yemeni capital Sanaa warned that recent steps taken by the Iran-backed militia, whether on its security or justice levels, aim at legitimizing crimes committed and to set the premise of trying hundreds of detainees.

The Houthi political move to eradicate inner surging opposition within coup ranks comes as news emerged on former President Ali Abdullah Saleh’s son, who is detained by the militias and suffering rapidly deteriorating health.

Saleh, a former ally to the Houthi-led insurgency, was killed earlier in December shortly after announcing that he would switch sides to join Yemenis backing the internationally-backed government—a move that isolated the Houthis.

Saleh had helped the Houthis win control of much of the country’s north, including Sanaa, and his decision to switch allegiances and abandon the Houthis was the most dramatic change on the battlefield in years. But the Houthis swiftly crushed a pro-Saleh uprising in the capital and shot him dead in an attack on his convoy.

Houthi militias stormed the houses of Colonel Mujahid al-Dulali, the accompanying bodyguard of Saleh’s nephew Brigadier Tareq Saleh.

Dulali’s house was looted and he was taken to an unknown location, sources in the General People's Congressbased in Sanaa told Asharq Al-Awsat.

Party leaders detained along with Saleh’s son are subjected to torture during Houthi interrogations, sources said. It is also likely that the militias transferred a number of senior military detainees to their main stronghold in Saada.

Congress members also received information leaks on Houthi detention camps, saying that Saleh’s son, after being tortured, had gone on a hunger strike.

Sources add that militiamen broke into and looted the home of pro-Saleh Colonel Essam Dweid.

Dweid, who is related to Saleh, and other members of his family were arrested.

The militias were able to suppress the armed uprising of Saleh supporters, which ended with the elimination of dozens of his civilian aides and house guards, confiscation of their funds and property and the arrest of hundreds of loyalists.

Most who were not taken are put on compulsory house arrest, in a move to foster fear and subdue the party into siding with the Houthis.

On the other hand, President Abedrabbo Mansour Hadi called on Yemenis to unite against the Iran-backed insurgents who shot Ali Abdullah Saleh dead as he fled the city following the collapse of their alliance.

"Let's join hands to end the control of these... criminal gangs and... open a new chapter to rid our beloved Yemen of this nightmare," Hadi, leader of the internationally recognised government, said in a televised address late Monday from Saudi Arabia, where he lives in exile.

The gruesome images from the previous day of Saleh, with a gaping head wound, sent shockwaves among his followers - a grisly end recalling that of his contemporary, Libya's Moammar Gadhafi, in 2011.

Saleh's son Salah said on Facebook on Tuesday that he would not receive condolences for his father's death until "after avenging the blood" of the longtime strongman. Healso urged his father's followers to fight their former allies, the Shia rebels known as Houthis.

"I will lead the battle until the last Houthi is thrown out of Yemen ... the blood of my father will be hell ringing in the ears of Iran," he said. 

Saleh, who ruled Yemen for three decades, had joined forces with the Shia Houthi rebels in 2014 when they took control of large parts of the country, including the capital, Sanaa.