Last Updated 4:10 p.m. ET
ALPHEN AAN DEN RIJN, Netherlands - A gunman opened fire with a machine gun at a crowded shopping mall outside Amsterdam on Saturday, leaving at least seven people dead and wounding 15 others, officials and a witness said.
The attacker was among the dead after fatally shooting himself at the Ridderhof mall in Alphen aan den Rijn, Mayor Bas Eenhoorn said. The suburb is less than 15 miles southwest of Amsterdam.
Eenhoorn said that children were among the victims, but he could not confirm whether they were among the wounded or dead, or both.
"It's too terrible for words, a shock for us all," he said.
The gunman's identity was known and it was "all but certain" he acted alone, District Attorney Kitty Nooy said, but investigators were not yet ready to release his name or age. She said he was a native Dutchman from Alphen who has a criminal record.
Witness Martine Spruit, a 41-year-old receptionist, told The Associated Press she was shopping at a drug store when she heard bangs and people in the store hid behind shelves. When they realized a shooting was taking place, customers shouted for employees to lock the doors.
"Then we heard the shots getting further away, so he was walking back and forth," she said. "Then we thought we'd have a look and there were two people lying dead near the entrance ... then he came back shooting so we locked the door again."
Queen Beatrix and Prime Minister Mark Rutte issued statements saying they were shocked and sympathize with the victims and their families.
A witness identified as Maart Verbeek told state broadcaster NOS the attacker had a machine gun and appeared to be shooting at random.
"There was a panic in the mall, a lot of people running," said Verbeek, a pet shop owner. "I see the attacker coming, walking, and I go inside the store ... and I see him going by with a big machine gun."
Hours after the shooting, residents continued to gather at the mall, some of whom appeared to be in a daze.
"You hear about this sort of thing happening at American schools and you think that's a long way away," said Rob Kuipers, 50, a project manager. "Now it's happened here in the Netherlands."
Eenhoorn said several other malls in the town were evacuated, but he would not elaborate on the reason. Dutch television broadcasters showed a bomb squad searching a car parked outside the Ridderhof mall that is believed to have belonged to the shooter.
Nooy said there was "no evidence" to support rumors the gunman was a former soldier, and confirmed his house has also been searched. She would not comment on reports that he left a note.
Witnesses said he had long blond hair, appeared to be about 25 years old, and wore a leather jacket with camouflage pants.
A resident who lives near the mall who gave his name as Marijn said the shooting went on for several minutes. When he went to see whether friends working at the mall were OK, he saw the shooter lying dead in front of a grocery store.
"There was glass everywhere," the resident said. "He was just shooting everywhere as if it were the Wild West."
Images published by the NOS showed the covered body of the shooter just inside a grocery store.
With his voice choking at times, Eenhoorn described the incident as a "disaster of unparalleled proportions" for Alphen, known as a quiet residential suburb, and it was all the more shocking because it took place on one of the first sunny days of spring.
"Under these circumstances, with many people shopping at the Ridderhof today, including parents with children, it's an almost incomprehensible situation," he said.
Although rare, shootings and violence are not unknown in the Netherlands. In 1999, four students and a teacher were hurt in a school shooting and in 2004, a teacher was shot dead by a student.
There have also been two assassinations in the past decade, the 2002 killing of right wing politician Pim Fortuyn by an animal rights activist and the 2004 murder of filmmaker Theo van Gogh by an Islamic extremist.
In 2009, a loner drove his car into a group of bystanders during a royal parade, killing eight and wounding 10.
Gun permits are difficult to obtain, but illegal automatic weapons and ammunition are frequently seized during drug busts.
Two people were killed in Alphen in a drug-related shooting several weeks ago. Nooy said investigators do not believe the incidents are linked. She said investigators were trying to trace the gun or guns used in the attack.
One unidentified witness on NOS television said he saw the shooter reload the magazine of his machine gun and continue to fire.
Police commissioner Jan Stikvoort denied reports police were slow to respond, saying they arrived while the shooting was ongoing and reached the gunman just as the shooting stopped.