The head of Israel's armed forces warned Syrian President Bashar Assad on Tuesday of "consequences" if fire continues from Syrian territory against Israeli troops in the occupied Golan Heights.

"If he disturbs the Golan Heights, he will have to bear the consequences," Lieutenant General Benny Gantz said in an address at Haifa University and broadcast on Israeli television.

Syrian opposition representatives have demanded international guarantees that President Bashar Assad step down in any peace deal, former opposition chief Ahmed Moaz al-Khatib said on Tuesday, as Russia and the United States step up efforts to organize a peace conference.

The demand was one of eight points set out in a roadmap agreed by delegates to a two-day Syrian National Consultation meeting in Madrid, Khatib said on his Facebook page.

An Abu Dhabi court will announce on July 2 its verdict in the trial of dozens of Emirati Islamists accused of plotting to seize power in the Gulf country, state news agency WAM reported Tuesday.

A total of 94 dissidents, eight of whom are tried in absentia, are on trial on charges of forming an organization with an aim to seize power.

Israel's Shin Bet domestic spy agency said on Tuesday it had foiled planned attacks on Israelis by two Palestinian Islamist groups in the Hebron area.

It said that, in March, Shin Bet, army and police uncovered a nine-man Hamas cell in the village of Bani Naim, south of the West Bank city, which planned to shoot dead an Israeli settler working in nearby fields.

Thousands gathered in Yemen's main southern city of Aden on Tuesday to call for renewed independence for the south 23 years after it united with the north.

Waving the flag of the former People's Democratic Republic of Yemen and portraits of exiled southern leader Ali Salem al-Baid, the protesters gathered at a square in the Khor Maksar district of Aden, Agence France Presse reported.

A planned Syria peace conference next month will only work if the government and rebels send credible negotiating teams, the U.N.'s deputy secretary-general Jan Eliasson said Tuesday.

"There have to be two, credible delegations to negotiate," Eliasson told reporters in Geneva, the planned venue of the talks.

Egyptian troops and policemen began sweeps of north Sinai on Tuesday ahead of a possible showdown with heavily armed gunmen who abducted seven security personnel, officials said.

A senior interior ministry official told Agence France Presse a "campaign has been going on for half an hour", while a policeman taking part in the operation told AFP that security forces traded fire with gunmen in a village in the restive peninsula.

Radical Salafist group Ansar al-Sharia, which Tunisian authorities have branded a terrorist organization, has called for a protest in the city of Kairouan on Friday against the arrest of its spokesman.

"Call to all Muslims to a protest in support of Ansar al-Sharia's spokesman Seifeddine Rais, in front of the headquarters of ruling Islamist party Ennahda near Bab Jalladine" in Kairouan, the group said on its Facebook page.

Saudi authorities have arrested 10 more suspects in an alleged Iranian spy ring unveiled two months ago, an interior ministry spokesman said on Tuesday.

The eight Saudis, a Lebanese and a Turk bring the number of people arrested to 28, the official SPA news agency quoted the spokesman as saying.

The U.N.'s children's agency warned Tuesday that up to 20,000 civilians, mainly women and children, could be trapped by harsh fighting in the Syrian town of Qusayr.

"The situation is desperate," UNICEF spokeswoman Marixie Mercado told reporters in Geneva.