Iran said on Monday it was hoping indirect talks with the United States could lead to a "positive" outcome for a prisoner swap.

Iran announced earlier this month that it was engaged in Oman-mediated talks with its arch-nemesis the United States over its nuclear deal and a possible prisoner exchange.

"We are negotiating for the release of Iranian citizens through parties who play a role in good faith," Iran's foreign ministry spokesman Nasser Kanani said on Monday.

Mobile phones are overheating and the pavement feels like a frying pan but for Abdul al-Assad, intense desert heat is all part of the hajj pilgrimage in summertime Saudi Arabia.

Even with temperatures hitting 46 degrees Celsius (115 degrees Fahrenheit), the 48-year-old Briton said the hardship only heightened his experience.

"If it was easy, it would be too easy," said Assad, a real estate agent, in Mecca, Islam's holiest city.

The Hezbollah movement said it shot down on Monday an Israeli drone that had flown into Lebanon's southern airspace near the border.

The Iran-backed group "shot down an Israeli drone that entered Lebanese airspace... near Zibqin in the south", Hezbollah said in a statement.

It published images of the purported drone, which it said was equipped with "two high quality cameras" and appeared largely intact.

The unmanned craft had travelled around seven kilometres (4.3 miles) into Lebanese territory, Hezbollah added.

Russian mercenary group Wagner has been seen for years as an armed extension of Moscow's influence in Syria and Africa but these overseas operations have now been called into question by its leader's failed revolt against the Kremlin.

After calling off his troops' advance toward Moscow, Wagner head Yevgeny Prigozhin is expected to go into exile in Belarus.

Hundreds of thousands of Muslim pilgrims walked or rode buses Monday to a giant tented city near Mecca for the climax of the annual hajj that Saudi officials say could break attendance records.

After performing the ritual circumambulation of the Kaaba, the giant black cube at Mecca's Grand Mosque that Muslims pray towards each day, worshippers set off for Mina, about seven kilometres (more than four miles) away, in suffocating heat.

At a livestock market in war-battered Yemen, goats and sheep meant to be slaughtered for the Muslim Eid al-Adha holiday are happily munching on hay, instead of leaving with a buyer.

The market trader Eiad al-Alimi expected better business this year, following a lull in fighting and renewed efforts to end Yemen's eight-year-long conflict.

But a grinding economic crisis -- marked by a collapsed currency and deepened by import bans and attacks on critical oil infrastructure -- has put holiday cheer on hold.

Sudan's army on Monday faced a multi-front challenge after losing Khartoum's main police base to paramilitaries in a battle that killed at least 14 civilians, while rebels attacked troops near Ethiopia.

The paramilitary Rapid Support Forces (RSF), fighting Sudan's regular army since mid-April, announced late Sunday a "victory in the battle for the police HQ" of the Central Reserve Police.

Fighting on Sunday between rival Sudanese generals in Darfur killed at least a dozen civilians, said a doctor in the devastated region.

Speaking from the capital of South Darfur state, the doctor said fighting there had led to "a provisional toll of 12 civilians killed in Nyala".

But the source -- speaking anonymously for security reasons -- noted that "the violence of the fighting restricts movement" of victims to hospital.

Residents on Saturday had reported battles, shelling and artillery strikes in Nyala.

Senegal captain Kalidou Koulibaly became the latest star name to head to Saudi Arabia on Sunday as he joined Al-Hilal from Chelsea, the Premier League club confirmed.

Koulibaly joined the Blues just last year from Napoli for a reported £33 million ($42 million).

However, the 32-year-old struggled in the Premier League as Chelsea finished 12th -- their lowest league finish since 1994.

"Kalidou Koulibaly has left Chelsea after completing a permanent transfer to Saudi Professional League side Al-Hilal," Chelsea said in a statement.

Indian Prime Minister Narendra Modi met Egypt's President Abdel Fattah al-Sisi in Cairo on Sunday on a rare visit during which both sides pledged to deepen their strategic partnership.

They agreed to boost investment by India, the world's most populous nation, in Egypt, which has the Arab world's largest population, of 105 million, and which is now in the grips of an economic downturn.

Modi, in power since 2014, was on his first visit to the north African country and US ally following a four-day trip to the United States where he met President Joe Biden.