German police have recovered a pipe bomb, an assault rifle and chemicals that can be used to make explosives after two suspects were detained in an overnight anti-terror raid near Frankfurt, prosecutors said Thursday.

A state interior minister said the arrests foiled a possible terrorist attack and the two suspects were linked to Islamic extremists, the dpa news agency reported.

The raid in the town of Oberursel came after security officials learned that three liters (nearly a gallon) of hydrogen peroxide had been purchased at a hardware store by someone using a false name, authorities said.

"This hydrogen peroxide triggered an alert," Frankfurt's deputy chief prosecutor Stefan Rojczyk told The Associated Press. "Police figured out who had bought it and it was decided to act fast."

In addition to the hydrogen peroxide, pipe bomb and assault rifle, 100 rounds of ammunition were also recovered.

Hesse state interior minister Peter Beuth identified the two suspects as a married couple, saying in state parliament that authorities foiled a possible terrorist attack with the raid, dpa reported. He added the two were believed to have links to the extreme Islamic Salafist movement.

Authorities identified the man as a 35-year-old German with Turkish roots, and the woman as a 34-year-old Turkish citizen, dpa reported.

Heavily-armed police wearing masks were involved in the overnight raid, and forensic officers in white suits entered the property and later carted out evidence during daylight hours on Thursday.

Hydrogen peroxide has been used by extremists to build improvised explosive devices in the past, including by the "shoe bomber" Richard Reid, who tried to detonate a bomb in his shoe during a trans-Atlantic flight

"Three liters is completely unusual," said Rojczyk. "You can use it to clear algae from your pond, but you can also use it to build bombs."

Rojczyk said a man and a woman were detained in the raid, but said he couldn't confirm that the two had links to Islamic extremism.

"He is a chemistry student," Rojczyk said. "We are of course still trying to determine what was going on. We have the devices, we have the owners of these devices, but now we need to find out what was planned. Everything is being evaluated and this may take some time."