DORTMUND, Germany (AP) German authorities arrested a suspected Islamic extremist Wednesday in their investigation into a bomb attack on a top German soccer team, while the team - missing a defender wounded in the blasts - lost 3-2 to Monaco in a hastily rescheduled Champions League match.
Amid heightened security, the defeat for Borussia Dortmund in Europe's top club competition came less than 24 hours after three explosions shattered a window of the team's bus and rattled nerves across the gritty city in western Germany.
Dortmund coach Thomas Tuchel said after the loss that he felt European soccer's governing body, UEFA, had not taken the attack seriously enough as it swiftly rescheduled the match.
''We weren't asked at all at any time,'' Tuchel said. ''Basically, we had the feeling that we were being treated as if a beer can had hit our bus, and half an hour later the decision was there that (it would be) tomorrow at 6.45 p.m. ... That gives you a feeling of powerlessness.''
Armed police officers in body armor patrolled the streets around Dortmund's stadium Wednesday night as locals and visiting fans mingled in a subdued atmosphere.
Supporters were banned from bringing backpacks to the match and some were frisked - with security officials even checking under their hats. During the match, small knots of armed police guarded access to the stands.
Earlier in the day, Frauke Koehler, a spokeswoman for German federal prosecutors, said investigators are focusing on two suspected Islamic extremists in the bus attack and searched their homes, arresting one of them. But authorities said other motives are possible.
Investigators are still trying to determine how the metal-packed devices were detonated and what explosive substance was used.
They also found three copies of a note at the scene of the blasts, which demanded the withdrawal of German Tornado reconnaissance jets that are assisting the fight against the Islamic State group and the closure of the U.S. Ramstein Air Base in Germany, Koehler said.
But the region's top security official raised the possibility the note could be ''an attempt to lay a false trail.''
''We are investigating in every direction,'' said Ralf Jaeger, the interior minister of North Rhine-Westphalia state.
Tobias Plate, a spokesman for Germany's Interior Ministry, said notes claiming responsibility haven't been a feature of past Islamic extremist attacks.
Koehler also said there were ''significant doubts'' about a second claim of responsibility on the internet suggesting a left-wing extremist motive.
As the investigation continued, the match delayed by the blasts got underway.
Dortmund was without Spanish central defender Marc Bartra, who underwent surgery for injuries to his wrist and arm after the three devices packed with metal pins detonated close to the team bus Tuesday night.
Before kickoff, his teammates honored Bartra by wearing yellow T-shirts bearing his image and the message in Spanish: ''A lot of strength - we are with you.'' The stadium announcer called out the Spanish defender's first name three times and the crowd roared ''Bartra!'' in response.
Clearly missing Bartra in defense and possibly still shocked by the attack on their bus, Dortmund conceded two goals in the first 35 minutes.
The team fought back after the break, to make it 2-1 in the 57th minute before Kylian Mbappe scored his second of the evening in the 79th minute for Monaco. Shinji Kagawa cut the deficit in the 84th minute, but it was not enough to save Dortmund from defeat.
''It was very difficult for the team to focus on the game. We let the players decide if they wanted to play today. But we noticed that training did us good,'' Dortmund coach Tuchel said.
''Up until kickoff, I had everything in my head, just not soccer,'' Dortmund midfielder Nuri Sahin said. ''I know soccer is important, but we are only human.''
Chancellor Angela Merkel branded the attack ''a repugnant act'' and praised the ''great solidarity'' shown by both teams' fans. German Interior Minister Thomas de Maiziere attended Wednesday's match.
UEFA, European soccer's governing body, increased security for all three Champions Leagues games on Wednesday.
Dortmund's compact stadium, packed with raucous home fans dressed in the team's distinctive black and yellow colors, is usually an intimidating venue for visiting teams, but both sets of supporters were united in their disgust at the attack. Some Monaco fans bunked down Tuesday night at the homes of strangers in Dortmund who offered them a place to sleep after the match was postponed.
Monaco fan Olivier Pourcel used the hashtag ''Bedforawayfans'' to find a place to sleep and in the process made a new friend.
''One of the Dortmund supporters sent me his message and invited me to his place, so we had a beer together. We had fun, and it was really nice, a good experience,'' Pourcel said. ''I have his number, he has mine, and when he will visit me in France, I will welcome him at my place.''
Before the match, Monaco fans even cheered Dortmund players as they checked out the pitch - and Dortmund fans responded by applauding rival supporters.
Dortmund is one of Germany's most popular soccer teams and a regular contender for the Bundesliga title, which it last won in 2012. It is in fourth place with six games left to play this season, 18 points behind leader Bayern Munich, Germany's dominant club of recent years.
Team flags flapped throughout the city Wednesday and dozens of fans gathered in a wind-swept parking lot outside the team's training complex in the morning, where four young women drew ''You'll Never Walk Alone'' in black markers.
Moulson reported from Berlin. Mark Carlson in Dortmund and David McHugh in Frankfurt contributed to this report.