A Turkish university on Tuesday revoked the university degree of Istanbul's powerful mayor Ekrem Imamoglu, the biggest political rival of President Recep Tayyip Erdogan, on grounds it was falsely obtained.

The ruling could hurt Imamoglu's plans to challenge Erdogan in the 2028 election, coming just days before he was to be formally named the main opposition CHP party's candidate for the race.

Under the Turkish constitution, any presidential candidate requires a higher education degree.

Mourners cried over the bodies of their loved ones with drones buzzing overhead early on Tuesday, as a wave of Israeli strikes plunged Gazans back into chaos.

"They opened the fire of hell again on Gaza," said Ramez al-Amarin, 25, a displaced Palestinian who lives in a tent in the southeast of Gaza City.

"There are bodies and limbs on the ground, and the wounded cannot find any doctor to treat them," he added.

Amarin said he transported several of his neighbours' children to hospital but there were no beds for them.

Residents of Gaza have been plunged into "abject fear" once again, a top UN humanitarian director said Tuesday, after intense Israeli strikes resumed on the Palestinian territory.

"Overnight our worst fears materialized. Airstrikes resumed across the entire Gaza Strip," Tom Fletcher, head of the United Nations Office for the Coordination of Humanitarian Affairs, told the UN Security Council in a video meeting.

"Unconfirmed reports of hundreds of people killed... and once again, the people of Gaza living in abject fear."

US military, be warned: after years of fighting in rugged terrain and weathering thousands of air strikes, Yemen's Huthi rebels are not to be taken lightly, experts say.

Despite a heavy US bombardment announced by President Donald Trump that left dozens dead, the battle-hardened, Iran-backed Huthis remain defiant, and with good reason.

The group from the mountainous north, which controls swathes of impoverished Yemen, has withstood a decade of war against a well-armed, Saudi-led international coalition.

UN chief Antonio Guterres on Tuesday said Gazans were being subjected to an "intolerable level of suffering" following the most intense Israeli airstrikes in Gaza since a fragile ceasefire took effect.

The strikes, by far the deadliest since the truce came into force on January 19, killed more than 400 people, according to the health ministry in Hamas-run Gaza.

Israeli Prime Minister Benjamin Netanyahu warned on Tuesday that massive overnight strikes on Gaza were "only the beginning" and that future negotiations with Hamas "will take place only under fire".

The strikes, by far the largest since a truce took effect in January, killed more than 400 people across the Gaza Strip, according to the health ministry in the Hamas-run territory.

Netanyahu said in a video statement on Tuesday evening "Hamas has already felt the strength of our arm in the past 24 hours. And I want to promise you –- and them –- this is only the beginning".

Hit by massive funding cuts and a crackdown on student protesters, Columbia University is under fire from US President Donald Trump, putting the world of higher education on tenterhooks.

The arrest of student activist Mahmoud Khalil has crystallized concerns over freedom of speech under the Republican leader's administration -- and fueled warnings that Trump is out to quell dissent.

Khalil, a US permanent resident with Palestinian roots, recently earned a graduate degree from the prestigious Ivy League school in New York.

Prime Minister Benjamin Netanyahu's bid to dismiss a top security official has threatened to plunge Israel back into deep political crisis, with opponents on Monday organising protests and a former court president warning against the "dangerous" move.

Netanyahu on Sunday cited an "ongoing lack of trust" as the reason for moving to sack Ronen Bar, head of the Shin Bet internal security agency, following a similar bid by the government to oust the attorney general.

Sudanese army forces advancing on Khartoum converged on Monday with troops in the capital's centre, a military spokesman said, increasing pressure on rival paramilitaries and inching closer to retaking the city.

The latest push by the army, at war with the paramilitary Rapid Support Forces (RSF) since April 2023, comes after troops had broken prolonged sieges on key military sites after months of apparent stalemate in Khartoum.

In a war-ravaged neighbourhood of Sudan's capital Khartoum, the stench from a gaping sewage pit is unbearable as Red Crescent workers pull a bloated body from deep underground.

The volunteers say 14 more remain below.

"They were shot in the head, some have crushed skulls," Hisham Zein al-Abdeen, head of forensic medicine at Sudan's health ministry, told AFP at the scene.

The victims, he said, were either shot or beaten to death before being thrown in.