German police say they have arrested two men on suspicion of buying bomb making materials and planning a major act of violence in the country.

Police say they detained a 24-year-old German of Lebanese descent and a 28-year-old Palestinian from the Gaza Strip in the capital, Berlin, on Thursday. Police say the men tried to purchase a large amount of chemicals that could be used to make an explosive device.

German officials say the suspects had not yet started to build a bomb and did not have any known links to terrorist groups. They say the two men were under surveillance for several months prior to being arrested.

Police also searched the men's apartments and an Islamic cultural center and mosque they attended in Berlin's Wedding district.

The arrests come several days before the 10th anniversary of the September 11th terrorist attacks on the United States and two weeks before a visit to Germany by Pope Benedict.

German officials have said the threat of terrorism against the country remains significant. German authorities also have thwarted a number of attacks by Islamic militants in recent years.