Belgian police on Tuesday shot and fatally wounded an alleged Islamist accused of gunning down two Swedish football fans visiting Brussels, as Sweden faces what its premier said was an unprecedented security threat.

The attack was launched in central Brussels late on Monday, when a gunman opened fire on Swedes ahead of a football match, killing two of them and wounding a third, before leading police on an overnight manhunt.

The suspect was cornered and fatally wounded early on Tuesday, when Belgian police moved to detain him in a cafe.

Russian President Vladimir Putin arrived in China on Tuesday to meet his "dear friend" Xi Jinping and bolster their relationship at a summit overshadowed by the Israel-Hamas war.

China this week welcomes representatives of 130 countries for a forum of President Xi's vast trade and infrastructure Belt and Road Initiative (BRI).

At the top of the guest list is Putin, who is on his first trip to a major global power since the Ukraine invasion threw his regime into international isolation.

An earring pokes out from under the helmet of Israeli army reservist Amir, a self-professed leftist who is pro-peace but finds himself looking through his rifle scope at buildings inside Gaza.

"It's surreal to be here", said Amir, one of more than 360,000 Israeli reservists called up for the war against Gaza-based Hamas militants.

Civilians one day, men and women like Amir become soldiers the next.

Israel has been bombing Gaza since Palestinian militants launched their bloody attack but tensions have also flared on the northern border with Lebanon, the base of another sworn enemy, Hezbollah.

Hundreds of Israelis have left villages and kibbutzim near the tense, UN-patrolled frontier with Lebanon following cross-border fire that has become more deadly as tensions have heightened.

The stench of death is overwhelming in Israel's National Center of Forensic Medicine, where experts have been trying to identify the remains of hundreds of people slain in the Hamas attacks.

Most of the bodies are riddled with bullets, mutilated or charred beyond recognition, say those performing the harrowing examinations.

Medical experts in pale green scrubs carefully study the remains and use DNA samples, fingerprints and dental records to try to identify the victims.

In some cases, they attempt to piece together severed body parts like macabre puzzles.

As Gaza's hospital morgues overflow with victims killed in Israel's bombardment triggered by a deadly Hamas attack, even an ice-cream truck has been used to hold corpses before their burial.

Israel has been pounding Gaza targets for days, seeking to wipe out the enclave's rulers Hamas after its militants broke through the militarised border barrier on October 7 to kill more than 1,400 people in southern Israel.

Colombia on Monday demanded that Israel's ambassador leave the South American country amid a worsening spat over President Gustavo Petro's remarks on the war with Hamas.

Foreign Minister Alvaro Leyva said the envoy, Gali Dagan, should "at a minimum, apologize and leave" after criticizing Petro's comparison of Israeli attacks on Gaza with the Nazi persecution of the Jews.

Leyva lashed out on social media at the "rudeness" of Israel's response to Petro, adding: "Shame."

Israel has one of the best-resourced militaries in the world, hugely supported by Washington. In Hamas, it faces a highly-trained armed group with powerful regional allies.

With both sides poised for a ground offensive in the wake of the deadly attack by Hamas on October 7, here is an overview of their military resources.

- Israel -

The Israel Defense Forces (IDF) number 169,500, of which 126,000 are army, according to Britain's International Institute for Strategic Studies (IISS).

Israel's war with Hamas in Gaza has stoked fear in the occupied West Bank, where dozens of Palestinians have been killed and residents say they now live in terror of more reprisal attacks by Jewish settlers.

The army battling Hamas after the Islamist group's bloody October 7 attack on Israel has also hunted the group's members in the West Bank, making hundreds of arrests.

Thousands of Palestinians have meanwhile rallied in solidarity with besieged and bombarded Gaza, and stone-throwing youths have burned tyres in clashes with Israeli forces.

The Gaza Strip has only "24 hours of water, electricity and fuel left", the regional head of the United Nations' World Health Organization told AFP on Monday, as pressure mounts for assistance to arrive.

If aid is not allowed into the besieged territory, doctors will have to "prepare death certificates for their patients," WHO regional director for the eastern Mediterranean, Ahmed al-Mandhari, said in an interview with AFP.