BEIRUT: Former Prime Minister Saad Hariri cautioned Monday that the credibility of the Arab League observer mission to Syria was at stake and slammed once more President Bashar Assad over the way he was dealing with the crisis in his country.

“The AL [Arab League] observers don't have much time, credibility is of essence and so far Bashar regime has been killing more and more,” Hariri said during a live session on his Twitter page Monday.

“Its time for AL observers to say the truth, the full story and not like Bashar regime wants it,” Hariri added.

In December, Damascus signed an amended agreement allowing in Arab League observers to oversee the implementation of a peace bid in the crisis-torn country.

The Arab League initiative calls on the Syrian government to withdraw the military from the streets, release political prisoners, allow journalists into the country and launch dialogue with the opposition.

However, the observer mission, which began its work late December, has been criticized from several sides, including from rights activists, the Syrian opposition and most recently by the head of the Arab Parliament, Ali al-Salem al-Dekbas.

Dekbas urged Sunday for the withdrawal of observers from Syria, saying the mission was allowing Damascus to cover up unabated violence and graft.

Echoing calls by the Syrian opposition, Hariri told his followers on Twitter that the observers needed to provide feedback about what they were seeing on the ground.

Responding to a question as to whether he thought the signing of the protocol by Damascus would put an end to the killing in Lebanon’s neighbour, Hariri said: “No I didn't [expect a change] and I said it [before], remember , but now if this week the AL observers continue without saying anything whats the point then?”

Hariri, a staunch critic of Assad, slammed once more the Syrian leader, saying he appeared to be using the observer mission to carry on with a crackdown the U.N. estimates has claimed the lives of over 5,000 people, mostly civilians.

“I feel the regime thinks that signing the protocol gives him [Assad] a license to kill,” Hariri tweeted in one post, adding: “Its unbelievable, Syrian regime says we want reform [and] the conclusion is more killing."

At the local level and in apparent criticism of Defense Minister Fayez Ghosn, Hariri dismissed reports that members of Al-Qaeda were operating in Lebanon.

"It's been 7 years talking about Al-Qaeda in Lebanon," Hariri said.

"It's all a big lie," he added.

Last month Ghosn said Al-Qaeda militants were sneaking into Lebanon under the guise that they were Syrian dissidents.

Ghosn’s statement have thrown Prime Minister Najib Mikati’s government, already torn apart by sharp differences over many key issues, into disarray after several top officials, including President Michel Sleiman, Mikati and Interior Minister Marwan Charbel either rejecting or voicing doubts on the claims that the Islamist group was operating on Lebanese soil.