Budapest (AFP) - Hungarian police said Sunday that an explosion in downtown Budapest that seriously injured two of its officers was caused by a homemade, shrapnel-laden device intended to kill the pair.
Detectives have launched a manhunt and opened an attempted murder inquiry following the incident late Saturday, Hungarian police chief Karoly Papp told a press conference.
"Our police officers were the targets of the attack. I consider it as an attack on the whole Hungarian police force -- it was aimed at executing them," he said.
The officers were on a foot patrol in the Hungarian capital when they were targeted with explosives, Papp added, without giving further details.
Papp did not comment on any possible terrorist link but said that "seven possible versions" of what happened were being considered.
The bomb was a homemade device packed with shrapnel, he added.
Papp described the suspect as a man aged between 20 and 25-years-old, 1.70 metres (five foot, seven inches) tall, thought to have been wearing a light-coloured fishing hat, blue jeans and white trainers.
"He will be found, and his motive discovered," Papp said, as he announced a 10 million forints (32,000 euros, $37,000) reward for information leading to the suspect's capture.
A 23-year-old female policewoman suffered life-threatening injuries due to the blast while her 26-year-old male colleague was also seriously injured, Papp said.
Their conditions have since stabilised, he added.
The blast occurred at 10:36 pm local time (2036 GMT) at a street-level shop on a major thoroughfare in the Hungarian capital.
- 'Send Brussels a message' -
Reports on the public M1 news channel said security cameras had recorded a bag being left at the scene by an unidentified man shortly before the blast.
Initial witness accounts said the large blast sounded like a gas explosion, although Hungary's rescue agency said there was no fire following the blast.
Bystanders posted pictures on social media of nails scattered across the scene.
The explosion, which was heard across central Budapest, blew out the ground floor shopfront and damaged nearby buildings and cars.
"There was a big explosion, I saw lots of smoke, and the window of the hostel I was staying in nearby was smashed," an American tourist told M1.
Police forensic personnel combed the area for clues through Sunday, while officers carried out door-to-door enquiries.
Hungary's national security parliamentary committee will meet Monday to discuss the blast, its chairperson told Hungary's MTI new agency.
The incident comes just eight days before Hungary's October 2 referendum on the EU's quota plan for the mandatory relocation of migrants.
Prime Minister Viktor Orban, a fierce critic of the EU's handling of the migration crisis, called the ballot in order to "send Brussels a message" that it should not force member states against their will.
The campaign has been marked by fears over public security and government posters that have strongly linked migrants to terrorism.
An opposition party had earlier urged the police to publicise the details of the blast as quickly possible, fearing the government might try to exploit the incident for political purposes.