The family of a US citizen detained for nearly seven years in Tehran pleaded Tuesday for his furlough to be with his father, who it said needs a new, urgent surgery and cannot leave Iran.

Baquer Namazi, 85, requires surgery within weeks to clear life-threatening blockages in his left carotid artery, which supplies blood to the brain, the family said.

He underwent a similar operation in October last year for blockages on the right artery, with Iran declining appeals to let him return to the United States for the treatment.

Israeli President Isaac Herzog visited the Bergen-Belsen Nazi concentration camp on Tuesday, retracing the footsteps of his father who helped liberate the site as a British army officer in 1945.

Recounting Chaim Herzog's first moments at the camp -- Isaac's father and former Israeli president -- the leader said he "stood on a wooden box, shouting in Yiddish before hundreds of skeletons".

"'Jews! There are still living Jews!" Herzog recalled his father saying.

Twenty-one separatist fighters and six members of Al-Qaeda's Yemen branch were killed Tuesday as an attack by the jihadists punctured months of relative peace in the war-torn country, government and security sources said.

Al-Qaeda in the Arabian Peninsula (AQAP) attacked positions held by the United Arab Emirates-trained Security Belt group in Abyan province in Yemen's south, the sources told AFP.

The violence came just days after the jihadist group released a video of a United Nations worker whom it abducted in the same province more than six months ago.

A bitter showdown between Morocco and its arch-rival Algeria over the disputed Western Sahara territory is causing diplomatic rifts with other nations and even risks sparking a full-blown conflict, analysts say.

"We're seeing a diplomatic war, where both sides are resorting to anything short of open conflict," said Riccardo Fabiani, North Africa project director at think-tank the International Crisis Group.

Western Sahara, a Spanish colony until 1975, is mostly desert but boasts immense phosphate resources and rich Atlantic fishing grounds.

Iran's Lake Urmia will dry out completely if rescue efforts are not prioritised over the needs of farmers in the drought gripping the region, an environment official said Tuesday.

The warning comes just four years after a Japanese government-funded programme had raised hopes of stabilising what was once the Middle East's largest lake and turning around one of the worst ecological disasters of recent decades.

A Palestinian was killed and 16 wounded Tuesday when Israeli troops entered Jenin in the occupied West Bank to carry out a home demolition, the Palestinian health ministry said.

"The outcome of the Israeli aggression on Jenin at dawn today: a 29-year-old martyr and 16 wounded with bullets and shrapnel were admitted to hospitals," the ministry said.

Palestinian official news agency Wafa identified the dead man as Mohammed Musa Mohammed Sabaaneh, 29.

Sabaaneh's father, Musa Sabaaneh told AFP that a soldier "inside a jeep fired a bullet" at his son.

A court in Iran has sentenced to death two gay rights activists on charges of promoting homosexuality, campaigners said Monday, urging pressure from the international community to stop the implementation of the verdicts.

The two women, Zahra Sedighi Hamedani, 31, and Elham Chubdar, 24, were sentenced to death by the court in the northwestern town of Urmia, the Hengaw Kurdish rights organisation said.

They were convicted of "spreading corruption on earth" -- a charge frequently imposed on defendants deemed to have broken the country's sharia laws, it added.

Palestinian-American journalist Shireen Abu Akleh, who was shot dead in May while covering clashes in the Israeli-occupied West Bank, was widely hailed for her bravery and professionalism.

Her killing, which her employer the Al Jazeera network, eyewitnesses and Palestinian authorities blamed on Israeli forces, sparked widespread grief and outrage which were compounded when Israeli security forces beat mourners at her funeral.

The Israeli army conceded Monday for the first time that one of its soldiers had likely shot Palestinian-American reporter Shireen Abu Akleh after having mistaken her for a militant.

"There is a high possibility that Ms Abu Akleh was accidentally hit by IDF (Israel Defence Forces) gunfire that was fired toward suspects identified as armed Palestinian gunmen," said the army's final investigation report into her May 11 death.

In a sun-baked cemetery in the central Iraqi city of Najaf, fresh are the graves of loyalists to Shiite leader Moqtada Sadr who were killed in clashes in Baghdad last week.

So too is seething anger following the face-off between the cleric's supporters, rival Iran-backed factions and the army that left more than 30 Sadrists dead and 570 others wounded.

Standing between tombstones, Moussa Abbas said the fight was far from over.