The UN High Commissioner for Refugees (UNHCR) warned late last month that there had been an "alarming escalation" in fighting in Yemeni northern restive provinces.

Sanaa-based National Organization for Defending Human Rights and Freedoms "HOOD" said in a statement obtained by Xinhua that " We warn against implicating Yemen into a sectarian civil war openly or secretly".

"We call for all Yemeni political forces not to be dragged into others' plots," it added, warning of deadly consequences that could harm the security and freedom of Yemeni people if such plots were implemented.

The warnings coincided with media reports that Houthi-led Shiite rebel group in northern province of Saada, where has witnessed the sporadic war between government troops and Shiite militants since 2004, set up new checkpoints in the north and arrested three Sunni men believed to be affiliated with the AQAP.

Sheikh Wazie Azeez Sadan, a tribal dignitary in northern province of Al-Jouf, told Xinhua that "Houthis have established six new checkpoints on the road that links Harf Sufian district of Amran province and Barat Al-Anan district of Al-Jouf province."

Sadan confirmed that "fears of possible outbreak of a sectarian war between Shiite rebels and al-Qaida were raised among northern tribes."

"There is a noticeable presence of Houthis in some districts of Al-Jouf, while a growing activity of al-Qaida leaders who travel frequently inside the province," Sadan said.