An injured person is taken to hospital after the shooting at a mall in Alphen aan den Rijn on Saturday. (AP)

Alphen aan den Rijn (Netherlands), April 9 (AP): A man opened fire with a machine gun at a crowded shopping mall outside Amsterdam today, leaving at least seven people dead and wounding 15 others, officials and witnesses 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 25km 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 realised 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 sympathise with the victims.

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 rumours 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.