STOCKHOLM, Sweden -- Swedish police used DNA testing in hopes of linking a 35-year-old drifter now in custody to the slaying of Foreign Minister Anna Lindh. But they said Wednesday he wasn't the only suspect and they were seeking at least five more people.

A week after Lindh, 46, was fatally stabbed in her stomach, chest and arms in a crowded department store, police were under intense scrutiny, particularly because of complaints they had not done enough after the 1986 assassination of Prime Minister Olof Palme, whose killer was never found.

The suspect, who was arrested Tuesday night, was put under a 24-hour suicide watch at police headquarters in Stockholm and DNA samples were being tested. Tore Olsson, of Sweden's national forensic laboratory, said police had collected DNA from a cap and knife left at the scene of Lindh's slaying.

Police also appealed for more information from the public, stressing the man in custody wasn't their only lead.

"They don't want to lock the target on a specific person," police spokeswoman Tina Gustafsson said. She added that investigators were pursuing other leads with "an open mind," including five other possible suspects.

Police have not released the details of a profile they developed of the killer.

Some Swedes wondered if the man in custody was really the murderer. He had been found eating at a restaurant outside Stockholm, even after police issued a warrant and national alert for his arrest.

"It feels like it's too simple, that he was just sitting there," said Angelica Bjerring, a 21-year-old nurse who helped bandage Lindh after she was stabbed.

Police released no details of their interrogations with the suspect, who is Swedish, and said results from DNA tests were expected today.

Lindh was stabbed as she shopped at the Nordiska Kompaniet department store. Like most politicians, including Palme, she did not use bodyguards. He was shot to death as he walked home from a movie theater in 1986.

A memorial service for Lindh was scheduled for Friday, with Secretary of State Colin Powell and leaders from Britain, Finland, Norway and Denmark attending.

To keep the suspect in custody, prosecutors must file a detention request by noon Friday. A detention hearing would then be Saturday.

Police declined to say what the man had told them after the arrest in Solna, outside the Swedish capital, citing secrecy rules.

Swedish media, quoting police sources, said the suspect had several prior convictions, including illegal possession of a knife and theft.

Lindh's death shocked the country and cast a shadow over Sunday's referendum to adopt the euro, which voters rejected. Lindh was a prominent supporter of adopting the single European currency, though authorities have said the attack did not appear to be politically motivated.

Palme's 18-year-old grand nephew Claes passed by the murder scene Wednesday, reading a sign saying flowers honoring Lindh should be placed by a condolence book at the main entrance. The mound of flowers and handwritten cards rose more than four feet.

"Since police had pictures (of the suspect), they're probably right. If it is the guy in the pictures, that is," Palme said, adding that his family was shocked to see another leading Swedish politician murdered.

Police said two other men were taken in for questioning, but were not considered suspects, adding that family members of the suspect were also questioned.

Authorities had filed a nationwide alert for the killer, including photos from the surveillance camera at the department store showing the suspected attacker clad in a baseball cap and gray hooded Nike sweat shirt. Police also circulated photos to other countries.