BERLIN (Reuters) - A man arrested in Germany on Wednesday on suspicion of storing materials that could be used as explosives had items in his apartment glorifying Islamic State, the regional police chief told broadcaster rbb.

Hans-Juergen Moerke told rbb that no attack plans had been found but a search of the flat had uncovered pyrotechnics, a gas mask, a replica Kalashnikov, camouflage suits and “many other IS trappings i.e. things that glorify IS”.

“We don’t have concrete connections (linking him to Islamic State) but this person did post photos on the internet in which he posed masked, with this Kalashnikov and Arabic characters,” rbb quoted Moerke, Brandenburg state police president, as saying.

Nerves are raw in Germany after a spate of attacks on civilians, including two claimed by the Islamic State group and a mass shooting in Munich by a deranged 18-year-old that was also initially seen as terrorism-related.

Moerke said the suspicion of terrorism against the 27-year-old German arrested in the eastern town of Eisenhuettenstadt - a man who he said had converted to Islam around seven years ago - “has not yet been ruled out”.

He said the man was known to police due to drug-related crimes and threats.

Earlier in the day a police spokesman said there were no signs the man had been planning a terrorist attack or any indications that he had an Islamist militant motive.

The website of German news magazine Focus initially reported that the man had a militant Salafist background and was suspected of plotting to attack a festival in Eisenhuettenstadt, near the Polish border, though it later quoted police sources as saying this was not the case.

The annual festival, where there will be a fairground, circus and a variety of musicians performing on stage, will begin with a lantern procession on Aug. 26 and run until Aug. 28.

Organizers of Munich’s annual Oktoberfest, the world’s biggest beer festival, have decided to tighten security in response to the July attacks, with a ban on rucksacks, security checks at all entrances and new fencing.