People walk between booths of the Christmas market in front of the city hall at the Marienplatz in Munich, southern Germany, on December 20, 2016, one day after a truck crashed into a Christmas market in Berlin. 聽AFP
BERLIN, Germany 鈥� German police hunted for the attacker in Tuesday鈥檚 truck attack at a Christmas market after prosecutors released a Pakistani asylum seeker who was arrested after the carnage.
鈥淲e can鈥檛 rule out that the perpetrator is on the run,鈥� Interior Minister Thomas de Maiziere told broadcaster ZDF, adding he was confident there would be 鈥減rogress鈥� in the inquiry.
The Pakistani was arrested late Monday after he was reportedly seen jumping out of the truck and fleeing the scene.
But officials had expressed growing doubts over whether they had the right suspect in custody.
ISIS has released a statement claiming the attack.
鈥淎 soldier of the Islamic State carried out the Berlin operation in response to appeals to target citizens of coalition countries,鈥� the ISIS-linked Amaq news agency said, without identifying the聽perpetrator.
READ: Islamic State claims responsibility for Berlin market attack听触听Truck rams into Christmas market; 12 killed
Berlin鈥檚 police chief Klaus Kandt earlier warned that 鈥渨e may have a dangerous criminal in the area鈥�, and announced security would be boosted while urging 鈥渉eightened vigilance鈥�.
Federal prosecutors said they had found nothing to link the Pakistani suspect to Germany鈥檚 deadliest attack in recent memory.
鈥淭he forensic tests carried out so far did not provide evidence of the accused鈥檚 presence during the crimes in the cab of the truck,鈥� the prosecutor鈥檚 office said.
As attention switched to the manhunt, investigators asked the public to send them any photos and video footage.
Twelve people were killed when the truck tore through the crowd, smashing wooden stalls and crushing victims, in scenes reminiscent of July鈥檚 deadly attack in the French Riviera city of Nice.
Another 48 people were injured, 24 of whom were released from hospital by late Tuesday.
The mangled truck came to a halt with its windscreen smashed, a trail of destruction and screaming victims in its wake, with Christmas trees toppled on their side.
Chancellor Angela Merkel 鈥� who visited the scene of the carnage for a minute鈥檚 silence and then joined a memorial service in the adjacent Kaiser Wilhelm Memorial Church 鈥� labeled the deadly rampage a likely 鈥渢errorist鈥� attack.
鈥楤odies everywhere鈥�
The Polish-registered vehicle, which was loaded with steel beams, had cut a bloody swathe of 60-80 metres (yards) into the market in the once-divided city鈥檚 inner west.
At least six of those killed were German citizens, authorities said, while countries from Israel to Spain said their nationals were among those injured in the busy tourist spot.
A Polish man, killed with a gunshot, was found on the truck鈥檚 passenger seat, said de Maiziere. He was believed to be the vehicle鈥檚 registered driver.
The Polish owner of the truck, Ariel Zurawski, confirmed Monday that the driver 鈥� his 37-year-old cousin 鈥� was missing, telling AFP: 鈥淲e don鈥檛 know what happened to him鈥� I鈥檝e known him since I was a kid. I can vouch for him.鈥�
Survivors recounted harrowing stories of near misses and carnage as festive partying turned to death and destruction in seconds.
鈥楩ree way of life鈥�
German flags flew at half-mast and mourners placed flowers and candles at the site.
Berlin鈥檚 landmark Brandenburg Gate was lit in the German national colours in honour of the victims.
The government declared that the city鈥檚 60-odd Christmas markets 鈥� after a one-day voluntary stoppage out of respect for the victims 鈥� should continue because 鈥渨e must not let our free way of life be taken from us鈥�.
Europe has been on high alert for most of 2016, with bloody jihadist attacks striking Paris and Brussels.
Germany also suffered two attacks in July in the southern state of Bavaria committed by asylum seekers and claimed by the ISIS group.
An axe rampage by an Afghan or Pakistani man on a train wounded five people, and a suicide bombing by Syrian asylum seeker left 15 people injured six days later.
The arrival of 890,000 refugees last year has polarised Germany, with critics calling the influx a serious security threat.
Merkel said earlier that if the attacker turned out to be an asylum seeker, this would be 鈥減articularly sickening in relation to the many, many Germans who are involved every day in helping refugees鈥�.
Marcus Pretzell of the anti-immigration Alternative for Germany party labeled the Christmas market victims 鈥淢erkel鈥檚 dead鈥�.
The attack in Berlin comes five months after Tunisian Islamist extremist Mohamed Lahouaiej Bouhlel ploughed a truck into a crowd on the Nice seafront, killing 86 people.
Merkel received calls of support from a string of foreign leaders, including French President Francois Hollande, Turkey鈥檚 Recep Tayyip Erdogan and Greek Prime Minister Alexis Tsipras, her spokesman Steffen Seibert said.
As well as sharing their condolences, they 鈥渟tressed the need for European solidarity in the fight against terrorism,鈥� Seibert said.
The White House said US President Barack Obama had offered Merkel assistance following 鈥渢he horrific apparent terrorist attack鈥�.聽CBB