Amnesty accused Syrian forces Wednesday of waging "relentless, indiscriminate" attacks against its people as a Syrian army defector warned the regime would use chemical weapons as a last resort.

The London-based rights group, which accompanied its report with video footage, said "civilians, many of them children, are the main victims of a campaign of relentless and indiscriminate attacks by the Syrian army."

The Syrian army and rebel forces clashed on Tuesday in the north of the country Tuesday for control of the Tall al-Abyad border post with Turkey, the Anatolia news agency reported.

Heavy machine gun fire and exploding shells could be heard from the Turkish side of the border near the town of Akcakale, where town hall officials asked residents by loud speakers to stay away from the border.

Iraq reopened its main Al-Qaim crossing with Syria to refugees on Tuesday, after closing it for several weeks, but continued to deny entry to single men under 50, an Iraqi official said.

Amr al-Khafaji, a spokesman for the displacement and migration ministry, which oversees the refugee camp at Al-Qaim, told AFP that 150 people had crossed from Syria on Tuesday.

Syrian Christian opposition leader George Sabra is set to meet Pope Benedict XVI on Saturday as part of an international group of Christian-Democrats, Italian media reported on Tuesday.

Sabra, who is the main spokesman for the Syrian National Council, the main exiled opposition group, will be received with some 100 other Christian politicians from around the world, ANSA and Adnkronos news agencies reported.

Iranian Foreign Minister Ali Akbar Salehi is to arrive on Wednesday in Damascus, where he will meet his counterpart, Walid Muallem and other officials, a Syrian government source said.

His visit comes on the heels a meeting in Cairo of the "contact group" on Syria -- grouping Iran, Egypt, Saudi Arabia and Turkey -- and attended by peace envoy Lakhdar Brahimi on Monday evening.

A group of Syrian refugees threw stones at U.N. peace envoy Lakhdar Brahimi's convoy on Tuesday as he left the Zaatari camp in Jordan where he pledged help despite the "worsening" conflict.

"Unfortunately, the situation in Syria is not likely to improve," Brahimi said during a brief visit to the camp in northern Jordan close to the Syrian border.

Saudi Arabia has barred Syrians from entering the country to perform the annual Muslim hajj pilgrimage, Syrian state media said Tuesday, marking the latest break between the two Arab nations.

"The Syrian High Committee of hajj has announced the halt to the pilgrimage this year, due to a failure to reach consensus with the Saudi authorities," the official SANA news agency reported.

Mitt Romney told donors the Palestinians "have no interest whatsoever" in peace with Israel and if elected president he would just kick the issue down the road, a leaked video showed Tuesday.

The Republican White House hopeful had already faced a barrage of criticism over initial excerpts from the May 17 fundraiser in which he writes off Democratic voters as "victims" that are beyond his help.

Egypt's public prosecutor on Tuesday ordered that seven U.S.-based Egyptian Copts be tried over their role in an anti-Islam film that sparked violent clashes around the world, his office said.

The seven -- Adel Riad, Morris Sadek, Nabil Bissada, Esmat Zaklama, Elia Bassily, Ihab Yaacoub and Jack Atallah -- were accused of "insulting the Islamic religion, insulting the Prophet (Mohammed) and inciting sectarian strife."

The international peace envoy for Syria Lakhdar Brahimi on Tuesday met Syrians staying at a Turkish refugee camp in his first encounter since taking over the mission from his frustrated predecessor.

The U.N.-Arab League envoy met representatives of some 1,300 Syrians at Altinozu camp in Hatay city, located on the border with their violence-racked homeland.