The international mediator for Syria, Kofi Annan, was due in Turkey Tuesday for a visit to Syrian refugee camps near the border, a Turkish diplomatic source said Monday.

"The visit will only last a few hours, ahead of Annan's trip to Iran," the official told AFP on condition of anonymity.

At least 24 people were killed Monday as Al-Qaida militants raided an army barracks, the latest in a spate of attacks by the terror network which has boosted its presence across Yemen's lawless south and east.

"Fifteen Al-Qaida gunmen were killed in clashes with members of the 111th Brigade in Loder in Abyan province," a stronghold of the terror network, the Defense Ministry 26sep.net reported.

An explosion on Monday hit a pipeline which supplies Egyptian gas to Israel and Jordan, marking the 14th such attack since 2011, security officials said.

According to witnesses, masked gunmen in two cars dug a hole near the pipeline in the al-Midan area close to the north Sinai town of al-Arish, placed the explosives inside and detonated them remotely.

Belgium said Sunday that humanitarian intervention in Syria under the protection of military forces would be needed if the regime of Bashar Assad pursues the "path of barbarism".

"The regime has taken the path of barbarism and I trust President Bashar Assad less and less," said Belgian Foreign Minister Didier Reynders on TV5 television.

Nearly 200 Jordanians demonstrated in Amman on Sunday to demand the release of 19 jailed political activists charged with insulting King Abdullah II.

The protesters, mostly Islamist youths, demonstrated outside the prime minister's office, urging the king to free the young activists.

Bahrain on Sunday turned down a request to transfer to Denmark a jailed Shiite activist who has been on hunger strike for two months and also holds Danish nationality.

"The handover of accused and convicted persons to foreign countries takes place under specific conditions... This does not apply in Abdulhadi al-Khawaja's case," a Supreme Judiciary Council official said, quoted by state news agency BNA.

Clashes between government troops and army deserters raged on Sunday across Syria, where at least 84 people were killed and more than 200 arrested, activists and monitors said.

The weekend escalation in violence came ahead of a U.N. deadline of Tuesday for regime forces to cease fire, prompting harsh words from international envoy Kofi Annan who said the escalation was "unacceptable."

Jordan's King Abdullah II on Sunday reiterated calls to find a political solution in Syria and avoid more bloodshed in the neighboring country, where thousands have been killed in violence.

"Jordan believes in finding a solution to the Syrian crisis in line with Arab consensus and believes in supporting (peace envoy) Kofi Annan," a palace statement quoted the king as telling a U.S. congressional delegation.

Pope Benedict XVI called on Sunday for an end to bloodshed in Syria and a commitment to dialogue to end the violence there, as part of a wider appeal to give hope to the entire Middle East.

"May the risen Christ grant hope to the Middle East and enable all the ethnic, cultural and religious groups in that region to work together to advance the common good and respect for human rights," he said in his traditional "Urbi et Orbi" message to mark Easter Sunday.

The international mediator for Syria, Kofi Annan, said on Sunday he was shocked by the "unacceptable" surge in bloodshed there despite a U.N. deadline for a halt to all violence next week.

"I am shocked by recent reports of a surge in violence and atrocities in several towns and villages in Syria, resulting in alarming levels of casualties, refugees and displaced persons, in violation of assurances given to me," Annan said in a statement.