After a three-week investigation, Philadelphia police arrested six people and seized $3.5 million worth of high-potency marijuana from a home in the Northeast yesterday, officials said.

Officers seized more than 300 pounds of marijuana when they raided the home in the 9000 block of Brous Avenue, said Inspector Aaron Horne, commanding officer of the department's narcotics unit.

Narcotics officers watching the house Tuesday saw a man place a large suitcase in the trunk of a car there, Horne said. The car then raced off, and officers followed, stopping the driver at Loretto Avenue and Roosevelt Boulevard, he said.

At the same time, officers saw five men leave the house. Police detained the men and secured the house and the car until a search warrant was obtained later that day, Horne said.

The probe began on a tip from an informant, police said.

Arrested were Carl Thomas, 33; Courtney Williams, 32; Steve Graham, 24; Wayne Hilliburton, 33; O'Neil Cumberland, 25; and Jermaine Perch, 27. All are Jamaican nationals; three live in New York state and three in Philadelphia, Horne said.

He said the marijuana had been grown indoors in water and chemicals instead of soil to increase the potency.

"It looks like this was a distribution place where individuals from around the tri-state area came" for bulk amounts, Horne said.

Police displayed the marijuana, which was in 25-pound bundles wrapped in thick black plastic and heavy tape. They said it appeared that mustard had been applied to the bundles to mask the smell of the marijuana.

Police credited the arrest and seizure to the work of Officers Matthew Beattie and Michelle Procter.