UN Secretary-General Ban Ki-moon demanded on Sunday that Syrian President Bashar Assad stop killing his own people, The Associated Press reported.

Delivering the keynote address at a conference in Beirut on democracy in the Arab world, Ban said the revolutions of the Arab Spring show people will no longer accept tyranny.

“Today, I say again to President (Bashar) Assad of Syria: Stop the violence. Stop killing your people,” Ban was quoted as having said.

Ban has been highly critical of the Assad government’s deadly crackdown on civilian protesters since the killings began. In August he said Assad had “lost all humanity.”

Ban’s comments, which were made in the same speech in which he called on Israel to end its “occupation” of Judea, Samaria and Jerusalem, come amid increasing concern that the Arab League’s mission to monitor conditions on the ground in Syria was failing.

On Thursday it was reported that the League is rethinking its observer mission and may decide to pull its monitors from the country altogether.

An attack on observers Monday in the city of Latakiya made it increasingly unlikely the League would send any more monitors to the country, sources said, “until the situation is suitable” for them to return.

Meanwhile, the League is set to review the work of its Syria monitoring mission later this month.

On Sunday, an Algerian who took part in the observing mission said Syria had threatened the observers with death and used women to try to seduce them.

Anwar Malek, a former Algerian army officer, told the London Telegraph that he fled the country after being constantly intimidated, following his witnessing the slaughter of women and children by security forces loyal to Assad.

“Blackmail ranged from threats of death, to public humiliation. We were meant to be monitoring a peace-keeping effort but instead watched people being killed, beaten up, and arrested by police, soldiers and militiamen,” he related.

Malek fled Syria last week after his car came under gunfire that he said was from supporters of Assad.

AP reported that the British-based Syrian Observatory for Human Rights said that at least five factory workers were killed on Sunday, when a roadside bomb detonated near the bus they were traveling in the town of Khan Sheikhoun in northern Syria.

The Observatory said 16 other people died in Syria Sunday, 11 of them in the restive central city of Homs.