Federal authorities on Wednesday announced an increased reward of $115,000 for information leading to the conviction of individuals responsible for the 2008 bombing in New York's Times Square.
The FBI, which had offered a $65,000 reward in 2013, said it was actively pursuing several "persons of interest" and has identified the origin of the explosive device's components.
"Someone knows those responsible for placing this device in the heart of New York City," Diego Rodriguez, head of the FBI's New York office, said. "We need those people to come forward to help us solve this crime before they can strike again."
The Times Square bomb exploded at about 3:45 a.m. on March 6, 2008, at the Armed Forces Recruiting Station, a small, stand-alone building. No one was wounded and the blast caused minor damage.
Authorities have said a suspect on a blue Ross bicycle dismounted, placed the bomb at the recruiting station, lit the fuse and fled. The bicycle was found in a dumpster several blocks away.
The suspect appeared to be working alone but could have had a lookout or a surveillance team of as many as five others, authorities said.
The FBI said the explosion might be connected to two other New York bombings, one at the British Consulate in 2005 and another at the Mexican Consulate in 2007.
The consulate bombs were also placed by someone on a bicycle and detonated between 3 a.m. and 4 a.m., authorities said.
The explosive device used in Times Square was detonated with a time fuse and built using an ammunition can commonly found on battlefields in Iraq and Afghanistan, the FBI said.
Despite years of investigations, no arrests have been made. The FBI said on Wednesday the case remained a "top priority."
In May 2013, Gerald Koch, a self-described anarchist from Brooklyn, was jailed after refusing to testify before a federal grand jury thought to be investigating the explosion. A federal judge ordered Koch's release in January 2014.
The announcement came on the second anniversary of the Boston Marathon bombing that killed three people and injured 264.
