The investigation into the weekend attacks in the US is moving fast. Officials have been sifting through evidence retrieved from the scenes of the blasts in New York and New Jersey, a stabbing spree in Minnesota, and a backpack loaded with explosive devices discovered in Elizabeth, N.J.
Security has been stepped up as members of the United Nations General Assembly gather in New York for a summit Monday.
Ahmad Khan Rahami, a 28-year-old citizen of Afghan descent, is wanted for questioning in connection with the three bomb incidents -- one in New York and two in New Jersey.
But as authorities investigate signs of a possible terror cell in New York and New Jersey, we round up what we know and don't know.
Live blog: Latest in the New York-New Jersey bombings
NEW YORK BLAST AND PRESSURE COOKER DEVICE
What we know: Twenty-nine people were injured when an explosion went off in the Chelsea neighborhood of New York at around 8:30 p.m. on Saturday. All of those admitted to hospitals had been released.
Shortly after the blast a few blocks away, investigators found a pressure cooker with dark-colored wiring connected by silver duct tape to what appeared to be a cellphone, officials said.
Surveillance footage shows the same man near the explosion, and where the pressure cooker was found.
On Monday police in New York said they're looking for 28-year-old Ahmad Khan Rahami in connection with the Chelsea bombing.
The FBI described Rahami as a U.S. citizen of Afghan descent with a last known address in Elizabeth, New Jersey -- the same city where an explosives-laden backpack was found Sunday night.
What we don't know: What the motive is behind the blast and whether the perpetrator acted alone or as part of a wider group.
Despite some similarities between the explosions in New York and New Jersey over the weekend, authorities haven't concluded if they're connected.
There have been no confirmed sightings of Rahami, and little is known about him beyond the description issued by the FBI.
Read more: Who is Ahmad Khan Rahami?
MINNESOTA MALL STABBING
What we know: ISIS said that a man who stabbed nine people at a Minnesota mall on Saturday evening was a "solider of the Islamic state", according to the ISIS-linked news agency Amaq.
The attacker has been named as 22-year-old Dahir A. Adan, according to two Somali community leaders who are in direct contact with his family.
He wore a private security company uniform, made a reference to Allah and asked at least one person if they were Muslim before he attacked, according to police and witnesses.
The stabbings at Crossroads Mall in St. Cloud happened in several stores, and off-duty police officer Jason Falconer has been hailed a "hero" after shooting dead the attacker who lunged at him with a knife.
What we don't know: CNN cannot independently confirm that ISIS was behind the attack.
Read more: Off-duty officer who shot attacker a hero
NEW JERSEY CHARITY RUN EXPLOSION
What we know: An explosion in a garbage can near a Marine Corps charity run in New Jersey on Saturday is being investigated as a possible terrorist act.
New Jersey State police want to question Ahmad Khan Rahami-- the same man wanted in connection with Saturday's bombing in New York -- in connection with the explosion.
Three pipe-bomb-type devices wired together were found near the boardwalk at the Seaside Park event, said officials, adding that the devices were rudimentary and only one of them detonated.
No one was injured in the blast -- most likely because registration problems delayed the start of the race, so no one was near the garbage can when the explosion happened.
What we don't know: Whether it's part of a weekend of co-ordinated attacks.
Investigators said they found similarities between this device and the bomb that exploded in New York's Chelsea neighborhood Saturday evening, but have not linked the two events at this time.
Read more: "We were lucky" say charity runners
ELIZABETH BACKPACK LOADED WITH DEVICES
What we know: A backpack containing up to five explosive deviceswas found in a wastebasket in Elizabeth, New Jersey, around 9.30 p.m. on Sunday.
The backpack was found outside a neighborhood pub and located about 500 feet from a train trestle, said the city's mayor Chris Bollwage.
Officers sent in a robot to examine the devices, causing one of them to explode. The remaining four devices will be transferred to the FBI laboratory at Quantico, Virginia, said Bollwage.
Ahmad Khan Rahami, the man wanted for questioning in connection with bombings in New York and Seaside Park, New Jersey, is also believed to be connected to the pipe bombs found in a backpack, sources said.
What we don't know: What exactly were these devices? "I don't know what they're made up of," said Bollwage of the package.