Belgian police arrested three more people on March 25 as investigations into March 23's suicide bombings by Islamist militants in Brussels threw up more links to killings in Paris last year.

Three suicide bombers struck security checkpoints in the southern Yemeni city of Aden on March 25, killing at least 26 people, residents and security sources said.

Islamic State fighters were on the retreat in the strategic Syrian city of Palmyra on March 25, as the United States said it likely killed several senior leaders of the militant group this week including its top finance officer

A French national suspected of belonging to a militant network planning an attack in France was arrested on March 24 morning, French Interior Minister Bernard Cazeneuve said.

Belgian police arrested six people in their probe of March 22's Islamic State suicide bombings in Brussels, while authorities in France said they thwarted a militant plot there "that was at an advanced stage."

The Democratic People's Republic of Korea (DPRK) successfully tested a solid-fuel engine that boosted the power of its ballistic rockets, state media reported on March 24, as the Republic of Korea (RoK)'s president ordered the military to be ready to respond to the DPRK's "reckless provocation."

Syrian troops backed by Russian air support fought their way into the Islamic State-held city of Palmyra on March 24, their biggest offensive yet against the jihadist caliphate, as Moscow and Washington discussed how to help to end the civil war.

US Secretary of State John Kerry is expected to press President Vladimir Putin over a political transition for Syria on March 24, after Europe's foreign policy chief turned up unexpectedly in Geneva to try to reinvigorate peace talks.

Australia said on March 24 that plane debris recovered earlier this month from Mozambique was highly likely to have come from Malaysia Airlines Flight MH370, which was carrying 239 people when it went missing more than two years ago.

One of the attackers in the Brussels suicide bombings was deported last year from Turkey, and Belgium subsequently ignored a warning that the man was a militant, Turkish President Tayyip Erdogan said on March 23.