DORTMUND, Germany, April 12 (Reuters) - Singing, munching Bratwurst sausages and swilling beer, Borussia Dortmund fans put on a show of defiance on Wednesday as they poured into their home stadium for their match against AS Monaco, postponed after an attack on the team bus a day earlier.
But the sea of fans, decked out in the team's black and yellow colours and accompanied by an increased police presence, could not quite shake off a feeling of shock after Tuesday's attack in which Spanish defender Marc Bartra was injured.
"We're down about what has happened," said Christoph Lewe, 51, who had travelled from nearby Essen with his 12-year-old son, Alexander, to the Champions League match. "But we'll be pleased if we win."
Earlier, German authorities arrested a suspected Islamist in connection with what Chancellor Angela Merkel called the "despicable" attack on the bus, in which three explosions went off as the Dortmund players made their way to the stadium.
The chancellor, who takes a keen interest in the fortunes of Germany's national soccer team, also praised Dortmund fans for taking in AS Monaco supporters overnight so they could stay on for the postponed match.
The solidarity prevailed as the two teams entered the stadium and prepared for the quarter-final match, with fans from the two teams drinking together and hugging each other.
"We're not just playing tonight for ourselves. We're playing for everyone!" Borussia Dortmund's managing director Hans-Joachim Watzke said in a tweet.
Inside the stadium, the Dortmund team warmed up wearing shirts bearing a picture of Bartra, who earlier said he was "doing much better" after surgery on a wrist injury sustained in the blasts.
Police, who banned backpacks from the Dortmund stadium, stepped up security for the rescheduled match and for a second Champions League quarter-final between Bayern Munich and Real Madrid.
Some fans of AS Monaco, which neighbours the southern French city of Nice where 86 people were killed in an Islamist attack last summer, were more relaxed than Dortmund supporters.
"In France, we know this," said Monaco supporter Pierre Calmon, 50, from Toulouse, who was attending the match with his son, 16-year-old Thomas. "We are pleased to spend another day in Germany."
Earlier, a spokeswoman for the Federal Prosecutor's Office, which handles probes into suspected terrorism, said the explosive devices had contained strips of metal.
Spokeswoman Frauke Koehler said investigators had found three letters near the scene, all with the same content suggesting a possible Islamist motive.
(Writing by Paul Carrel; Editing by Angus MacSwan)