SANAA, Yemen, Shiite Houthi fighters, torn apart images of their allied party's leader, ex-president Ali Abdullah Saleh, that were erected on massive billboards, in the Yemeni capital, Sanaa.

The move came, hours after Houthi leader, Abdel-Malek al-Houthi, launched a verbal attack in a speech, against Saleh and his party, accusing them of committing a national betrayal, through working secretly with their enemy, a Saudi-led Arab coalition.

This is a very dangerous signal of internal split between the strongest allies, Houthis and Saleh, which is clearly threatening an eruption of a new civil war, in the already war-stricken Yemen.

The huge images of Saleh were erected a day earlier, across the major streets of Sanaa, by his party, in preparation to celebrate the 35th anniversary of establishing the General People's Congress (GPC), on Aug 24.

Saleh's images were distorted badly, as the Houthis packed the streets with their new security checkpoints and patrol military vehicles, in a stark defiance to Saleh and his party.

There were no immediate reaction yet from the party of the strong man, whose GPC party is considered the largest political party, representing the majority of Yemen's 26 million population, according to the latest elections' state statistics.

Houthis allied with Saleh before the beginning of the war, launched against them by their foes of the internationally-recognised government of exiled President, Abd-Rabbu Mansour Hadi, and the Arab military coalition, led by Hadi's ally, Saudi Arabia.

On Saturday, Houthi leader, Abdel-Malek al-Houthi, made an unprecedented speech, accusing Saleh and his party of letting down the internal front line and retreating their military loyalists from anti-coalition battlefronts.

"Saleh and his GPC party have been ordering their military loyalists to retreat from the battlefronts and working with the Saudi-led enemy," Houthi leader, Abdel-Malek, said, in his speech that aired through the group media.

"They (Saleh and his party), serve the enemy to implement its goals and help the enemy to carry out attacks and advances," al-Houthi said, accusing Saleh and his party of the greatest national betrayal.

The Houthi leader also strongly criticised Saleh, for massing crowds for the Aug 24 GPC celebration, saying, "We have made it clear that the period is not an election stage, to mass large crowds, but the period is a war and those efforts must be directed to reinforce the battle fronts."

Al-Houthi also blamed Saleh and his party for failure in facing the coalition forces, saying, "Saleh is the main cause of the failure in the front lines and he, along with his party, were behind the severe deterioration of the humanitarian situation to the lowest level."

"We have been stabbed in the back, while we at the same time went with all sincerity to the front lines, to fight the aggression," al-Houthi said, in reference to Saleh.

"He went with us (to the front lines) with only his finger, while he kept his legs there in the back," al-Houthi said, pointing to Saleh's role.

Yemen's internationally-backed government, allied with the Saudi-led Arab military coalition, has for more than two years been battling Shiite Houthi rebels and their allied party of former President Saleh, over control of the country.

The coalition began military air campaign in Mar, 2015, to roll back Houthi gains and reinstate exiled President Hadi to power.

The coalition also imposed air and sea blockade, to prevent weapons from reaching Houthis, who had occupied the capital, Sanaa, militarily and seized most of the northern Yemeni provinces since the late 2014.