Brussels

The Islamic State group on Sunday claimed responsibility for a weekend machete attack that wounded two policewomen in the Belgian city of Charleroi, calling it an act of reprisal carried out by one of its "soldiers."

Belgian authorities have raided dozens of homes and arrested 12 suspects in a major anti-terror investigation which they said required "immediate intervention."

Belgian authorities have charged two more men with offenses related to the Brussels bombings.

The attackers who struck Brussels on March 22 initially planned to launch a second assault on France, Belgium's Federal Prosecution Office said Sunday.

The arrest Friday of five men suspected of links to the Brussels bombings, including the last known fugitive in last year's Paris attacks, raised new questions about the extent of the Islamic State cell believed to have carried out the intertwined attacks that left 162 people dead in two countries.

Democrats said Tuesday they will push proposals to boost security at airports, train stations and other transportation hubs in response to attacks in Brussels and elsewhere.

Still reeling from attacks in Brussels and Paris, world leaders are wrestling this week with the chilling prospect of the Islamic State group or other extremists unleashing a nuclear attack on a major Western city.

Two more Americans have been identified as killed in the attacks on Brussels, the State Department confirmed Sunday, bringing to four the total number of U.S. citizens confirmed as victims.

Belgian prosecutors announced they have charged three men with terror offenses over the suicide attacks on the Brussels airport and subway, as organizers canceled a solidarity rally at the government's request because police are too strapped to cope.

President Barack Obama is offering his prayers for the families of the two Americans killed in the bombings in Brussels and telling Belgians that "America has their back" in the fight against terrorism.