The Houthi Group has been setting up new checkpoints in Jawf province to inspect cars after a deadly car-bomb killed and injured many of its followers while they were on way to mark Day of Al-Ghadir.

Some 15 checkpoints were built in the areas of Al-Motoun, Al-Zahir where the blast took place, and Al-Matama, tribal sources have said.

In the meantime, the UN has voiced concern about possible sectarian conflict in northern Yemen after two car bomb attacks in November targeted Houthis in Jawf and Saada provinces.

The UN said on its website IRIN its concern was based on local reports highlighting rising tensions between the group and Al-Qaeda in the Arabian Peninsula which claimed responsibility for the attacks.

AQAP said the attacks had been carried out by newly-formed special units to defend the Sunnis.

These units are also responsible for eradicating 'the malice' Shias, mainly Rafidah sect, have planted in northern Yemen, it said.

The UN also said that the Houthi Group had arrested some people it suspected they were Al-Qaeda members.

Last month, two car bomb blasts targeted Houthi convoys: one in Jawf on its way to celebrate Eid Al-Ghadir, and the second while on its way to show respect at a funeral in Saada.

About 27 Houthis were killed and almost a dozen others were wounded in the bombings.

Before AQAP emerged to say it was behind the attacks, Houthis accused the U.S. and Israeli intelligence agencies of orchestrating the Jawf blast and accused the U.S. mission in Sana'a, namely U.S. envoy Gerald Michael Feierstein, of involvement in the Saada blast.

Feierstein gave money to tribal leaders during his visits to some northern areas including Amran to carry out the attack, the Houthi information bureau claimed.

In response, the U.S. embassy condemned the attacks against innocents, as it dismissed the Houthi accusations as ridiculous and baseless.