A fourth round of nuclear talks between Iran and six world powers ended Friday with both sides complaining that major gaps remained ahead of a July 20 deadline for a vaunted accord.

Iran's chief nuclear negotiator Abbas Araqchi quoted on state television, reported "no tangible progress" at the talks in Vienna as he described the gaps as "too huge."

Iran is recruiting Afghan refugees to fight in Syria to reduce casualties among Iranian Guards personnel and Hizbullah, a Western official said late Thursday.

Tehran strongly denies its forces are directly involved in the Syrian conflict but Hizbullah publicly acknowledged in April last year that it has been fighting alongside President Bashar Assad's troops.

An Argentine court Thursday declared unconstitutional an agreement with Iran to probe the 1994 bombing of a Buenos Aires Jewish center, with a final decision left to the Supreme Court.

The government, which vowed to appeal, holds that Tehran was behind the attack on the Argentine Jewish Charities Federation, or AMIA, that left 85 people dead and 300 others injured two decades ago.

Foreign Minister Jebran Bassil has discussed with his Saudi counterpart Prince Saud al-Faisal the presidential deadlock as al-Mustaqbal movement leader ex-PM Saad Hariri intensified his meetings to avoid a vacuum, An Nahar daily reported on Wednesday.

The newspaper said that Bassil held long discussions with al-Faisal on Tuesday, which required him to stay another day in Riyadh.

Iran is investigating claims that guards at Evin Prison beat inmates during a routine inspection last month, one of the country's vice presidents said Wednesday.

The April 17 incident inside the jail's Section 350, which holds political prisoners, prompted relatives of inmates to protest outside the presidency.

Diplomatic efforts by Iran and world powers towards a potentially historic nuclear deal entered uncharted territory Wednesday with a new round of talks in Vienna.

After three meetings that Washington says have enabled both sides to "understand each other's positions", the negotiators aim this time to start drafting the actual text of an accord.

Iran is sharing nuclear technology with North Korea, Israeli Prime Minister Benjamin Netanyahu said in an interview published Wednesday, as Tehran and world powers hold talks aimed at ending a decade-old standoff.

Netanyahu, who is in Japan this week for talks with Prime Minister Shinzo Abe and Foreign Minister Fumio Kishida, said Iran "would share whatever technology it acquired with North Korea," the Mainichi Shimbun reported in a front-page piece.

Thousands of Iranian women have come together in an online campaign for greater social freedoms, posting pictures of themselves flouting the Islamic dress code required of all women in public.

More than 146,000 people have supported the Facebook page "Stealthy Freedoms of Women in Iran," which was created just 10 days ago with the aim of sparking debate on whether women should have the right to choose to wear the hijab.

The prime ministers of Japan and Israel compared notes Monday about living near countries with suspected illicit nuclear weapons programs.

Benjamin Netanyahu, on the second day of a five-day trip to Japan, said the international community should keep up pressure on Iran, which the West suspects of trying to develop atomic bombs.

The United Nations' atomic watchdog said Sunday it would hold talks with Iran to discuss its long-stalled probe into Tehran's alleged past efforts to develop nuclear weapons.

"IAEA and Iranian officials will meet on Monday in Vienna for further discussions within the Framework for Cooperation," International Atomic Energy Agency spokeswoman Gill Tudor said.