Boston's annual city-wide celebration descended into chaos Monday when two bombs near the Boston Marathon finish line exploded, killing three.
Broadcast and cable news networks in the U.S. along with news shows around the world have been leading broadcasts with coverage of the incident.
Here is a look at the latest key developments as of early Tuesday:
* THE LATEST ON THE VICTIMS:
The death toll continued to stand at three as of early Tuesday morning, according to a variety of news organizations.
A Boston hospital representative said in an update carried by BBC News that others remain in difficult medical conditions.
The exact number of injured people remained unclear.
The Boston Globe early Tuesday mentioned that "more than 130" people had been hurt. The Wall Street Journal spoke of "around 140." Various reports late Monday had mentioned 144-plus injured people.
* POSSIBLE SUSPECTS:
The Associated Press reported that as of late Monday evening, authorities had no suspects in custody.
A Saudi national questioned on Monday is believed to be a university student in Boston and has been cooperating with the FBI, according to the Boston Globe. He told agents that he was not involved in the explosions and simply ran away from them out of fear, the Globe says, confirming earlier reports. "Investigators did not characterize the man as a suspect," it added.
President Barack Obama, in a brief televised address, said he would put the full resources of the government behind the investigation. "Make no mistake. We will get to the bottom of this and we will find out who did this and we will find out why they did this," he said.
Meanwhile, BBC News reported on Tuesday that Massachusetts State Police said that a search warrant had been issued for a property in the Boston suburb of Revere. Further details weren't immediately available. The report reiterated that the FBI has launched a probe described as a "potential terrorist inquiry."
* MORE "SUSPECT DEVICES"
Counter-terrorism officials found five additional "suspect devices" on Monday, the Wall Street Journal reported overnight. But it cited a law enforcement official as saying that investigators did not believe the devices, which were being analyzed, were undetonated bombs.
The New York Times quoted Massachussetts governor Deval Patrick as saying that Boston would be open for business on Tuesday.
* NBA GAME, LONDON MARATHONG, MARGARET THATCHER FUNERAL AND OTHER AFFECTED EVENTS:
The NBA has canceled Tuesday’s Boston Celtics game against the Indiana Pacers because of the marathon tragedy, Boston.com reported.
Meanwhile, police presence and security measures have been stepped up in major cities around the world, including London and Paris.
The London police force is reviewing security plans for Wednesday's funeral of former British Prime Minister Margaret Thatcher, the BBC reported Tuesday morning. Security measures were already a big focus before the Boston bombs, due to the former PM’s contentious legacy.
Meanwhile, as of early Tuesday, the London Marathon was expected to take place as scheduled on Sunday, sports minister Hugh Robertson told the BBC. Organizers confirmed that.
Robertson said London mayor Boris Johnston was set to meet police chiefs on Tuesday to discuss the situation and security measures. London officials were also waiting for more information from U.S. authorities about the Boston bombs.
Robertson said the London Marathon would only be canceled for security reasons or out of respect for the Boston victims. Discussing security, he said: "We deal with this on a daily basis...so you can have confidence... As of now, there is absolutely no threats... The marathon already had very detailed security plans. We have enormous experience doing this."
So, while security measures will be reviewed as always in the case of major events, "we will deliver a safe and secure marathon," he vowed.
Meanwhile, a BBC representative told The Hollywood Reporter that coverage plans for the London Marathon would be discussed on Tuesday following the Boston bomb detonations. The BBC had so far planned five hours of live coverage of the event.
* DIGITAL MEDIA:
Google-owned YouTube has created a spotlight video page called "Explosions at Boston Marathon."
Devoted to all video related to the bomb blasts, the page includes Obama's Monday speech about the tragedy, police press conferences, as well as amateur videos from onlookers.
Meanwhile, Twitter has suspended a fake Boston Marathon account promising to raise donations for victims, the CBS TV station in Sacramento reported.
The suspended account, @_BostonMarathon, asked for re-tweets in return for $1 donations to the victims. But the real Boston Marathon Twitter handle is @BostonMarathon, the report said.
Patrick Brzeski contributed to this report.