Bonn - German prosecutors applied Saturday for arrest warrants for two terrorist suspects escorted off an Amsterdam-bound plane at Cologne airport.

Chief prosecutor Fred Apostel said evidence provided by police showed the pair "were planning to carry out an attack in the near future."

The two men, a Somali national aged 23 and a 24-year-old German born in Mogadishu, were taken off a Dutch KML airliner on Friday morning minutes before it was due to take off.

Security sources said the men had been under observation for months and were planning to travel via the Netherlands to a training camp for militants on the Pakistan-Afghan border.

A search of their apartment had turned up letters in which the two men in the 20s had declared their readiness to die in a jihad or holy war, the sources said.

Police apparently stepped in to prevent them from linking up with members of the Islamic Jihad Union, (IJU), often described as a successor to the terrorist network al-Qaeda.

German police are currently searching for two other militants who underwent training in the use of firearms and explosives at an IJU camp and are now believed to be back in Germany.

Police fear Eric Breininger, a 21-year-old German convert to Islam, and Houssain al-Malla, a 23-year-old Lebanese, might be planning terrorist attacks in Germany.

Breininger, who is from Saarland state in the west of the country, is reported to have recorded an internet video in which he spoke of carrying out a suicide attack and supporting jihad. (dpa)