Saudi Arabia on Monday reported three shells hit the Arar area inside the country along its border with Iraq, where jihadist-led militants have gone on the offensive.

"Three shells struck near a residential complex in the northern border area, without causing casualties," a border guards spokesman said, adding that an inquiry into the origin of the shelling was under way.

A Saudi court on Sunday sentenced to 15 years in jail a prominent rights lawyer described by Amnesty as a prisoner of conscience, relatives said in a statement posted on Twitter.

The tweet said that Waleed Abulkhair, who has had many run-ins with the authorities over his activism and for allegedly insulting authorities, was also banned from traveling abroad for 15 years and fined 200,000 riyals (around $54,000).

A Saudi security officer and a Yemeni soldier were killed in an attack on a border post between the two countries on Friday, officials said.

The interior ministry in Riyadh said a border security patrol came under fire near the Wadia post in the southern province of Sharura, killing the unit's chief.

The surprise declaration of a "caliphate" by jihadists accused of committing atrocities in Syria and Iraq has provoked an outcry even among Islamists who dream of a state under Sharia law.

The caliphate, an Islamic system of rule, was abolished nearly 100 years ago, although many Arabs and Muslims still associate it with a golden age.

The Philippines urged its large Muslim minority on Thursday to reconsider plans to join pilgrimages to Saudi Arabia this year due to a deadly virus outbreak there.

About 6,500 Filipinos who are set to join the annual Hajj pilgrimage in October are being urged to go next year instead, when the Middle East respiratory syndrome (MERS) is expected to be under control, health department spokesman Lyndon Lee Suy said.

Saudi Arabia pledged $500 million in humanitarian aid for Iraq on Tuesday, to be disbursed through the United Nations to those in need regardless of sect or ethnicity, state media reported.

King Abdullah "has ordered $500 million in humanitarian aid to the brotherly people of Iraq affected by the painful events, including the displaced, regardless of their religion, sect or ethnicity," a foreign ministry spokesman told the official SPA news agency.

Saudi security officials are in Beirut to follow up the results of the investigation into the Duroy Hotel blast last week which was carried out by a Saudi suicide bomber, An Nahar daily reported Tuesday.

Pan-Arab daily Asharq al-Awsat said Friday that the delegation's visit is aimed at identifying the suicide bomber. But according to An Nahar, the officials would only seek information on the probe.

Saudi King Abdullah appointed a new spy chief, giving the job to the former deputy defense minister days after sacking him from that post, SPA state news agency reported Tuesday.

Prince Khaled bin Bandar bin Abdul Aziz had been unexpectedly removed from his post on Saturday at the request of his boss the defense minister, after only 45 days on the job.

A Saudi citizen kidnapped in Yemen has been freed by his abductors and returned home on Sunday after "huge efforts" to secure his release, the foreign ministry said.

In a statement carried by the official SPA news agency, the ministry gave no details on when Ayedh bin Jibran Mikali had been abducted or who had kidnapped him.

Saudi King Abdullah on Sunday sharply criticized religious extremists, vowing not to let "a handful of terrorists... terrify Muslims", in a speech marking the start of the Muslim holy fasting month of Ramadan.

Islam is "religion of unity, fraternity and mutual support" but some people "lured in by false calls... are confusing reform with terrorism", the monarch said, in comments carried by state news agency SPA.