German investigators said Monday a 22-year-old Syrian who is accused of planning a terrorist attack had links to the Islamic State group, and was handed over to police after being bound and held captive by three other Syrians.
There was an "IS context" to the attacks planned by Jaber al-Bakr and an alleged accomplice, said Joerg Michaelis, who heads up the criminal investigation office of the eastern state of Saxony where he was arrested.
"The approach and behaviour of the suspect indicated an IS context," Michaelis told a press conference. Al-Bakr had been searching the internet for information on explosives, he said.
Germany's domestic intelligence agency BfV received a tip at the beginning of September that the Islamic State extremist group was planning a terrorist attack on infrastructure in Germany, according to the head of the organization, Hans-Georg Maassen.
"We had clues from intelligence gathering that at first he wanted to attack trains in Germany," Maassen told state broadcaster ARD.
"In the end the plan became more concrete to attack airports in Berlin."
Al-Bakr appeared before the court in the eastern city of Dresden after being arrested overnight in a raid on an apartment in nearby Leipzig.
Police launched a manhunt for Al-Bakr on Saturday after discovering what authorities said was 1.5 kilograms of dangerous explosives and other material - similar to that used in attacks in Paris and Brussels - in an apartment in a housing block in Chemnitz.
An alleged accomplice, identified as Khalil A., has also been taken into custody.
Al-Bakr had sought refuge in the Leipzig apartment of another Syrian, who he met at the city's railway station.
After recognizing al-Bakr from official material about the search the Syrian turned up at a Leipzig police station and showed them a mobile phone photo of al-Bakr.
Police later stormed the Leipzig apartment where they found al-Bakr tied up with two people standing guard over him, Michaelis said.
"The suspect was bound when handed over to us," said Michaelis.
"Our thanks go to the man from Syria, who informed the police about the whereabouts of the suspect, and has thus decisively contributed to the arrest," said a spokeswoman for German Chancellor Angela Merkel.
Khalil A., who was detained by police on the weekend, had rented the Chemnitz apartment where the explosives were found and which has been under observation by security forces since the middle of last month. Khalil A. has been in Germany since November.
Al-Bakr, who narrowly avoided capture on Saturday morning during a police raid on the Chemnitz apartment, was caught after the authorities stormed the Leipzig apartment shortly after midnight.
Police have also been forced to defend their handling of Saturday's raid, saying that they had to proceed cautiously because the apartment building had not been evacuated.
Michaelis stressed the "incalculable risk" involved in the operation to move on an apartment possibly containing a large amount of explosives.
The arrest of al-Bakr, who entered Germany illegally in February 2015 before gaining asylum status, also resulted in Merkel facing renewed political pressure from her critics.
Horst Seehofer, who is Bavarian premier and heads up the Christian Social Union, the Bavarian-based allies of Merkel's Christian Democrats, renewed his call for comprehensive checks of all refugees.
About 890,000 refugees arrived in Germany in 2015, many fleeing Syria's five-year civil war, after Merkel opened up her nation's borders to allow refugees stranded in Hungary to travel to Germany.
Germany has been on high alert since two refugees carried out Islamic State-inspired terrorist attacks in the space of one week in July.
A German Interior Ministry spokesman said there had been no change in the security situation in the country as a result of al-Bakr's arrest, but stressed that the nation remained a target of international terrorism.
At least five Islamist attacks have been thwarted by German police since 2007.