They lost the game, but realised there is more to life than soccer.

Just a day after an explosives attack on their team bus, Borussia Dortmund's frustration at losing 2-3 to AS Monaco in their postponed Champions League clash was eclipsed by their players' relief at being alive.

"I don't know if the people can understand this but, until I was on the pitch in the second half, I didn't think about football," Dortmund player Nuri Sahin said after Wednesday's match.

"Last night, I didn't realise what happened until my wife and son were waiting in front of the door and there I felt how lucky we were," he recalled. "I get goosebumps."

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.

"When we were in the bus last night, I can't forget the faces," said Sahin, speaking English to the Viasat Football broadcasting network. "I will never forget these faces."

Spanish defender Marc Bartra, injured in the attack, said he was "doing much better" after surgery on his wrist. His team mates wore shirts bearing his picture during their warm-up for the match, which turned out to be a pulsating encounter.

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.

An exit from the Dortmund stadium was briefly closed as police examined suspicious packages, but quickly re-opened.

Dortmund coach Thomas Tuchel said his team would have liked more time to take stock after the attack and felt ignored by the soccer authorities after being made to play less than 24 hours later.

"I encouraged everyone to take the game seriously but football is not the most important thing in the world," he said.

Merkel, who takes a keen interest in the fortunes of Germany's national soccer team, earlier praised Dortmund fans for taking in AS Monaco supporters overnight so they could stay on for the postponed match.

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."