The two accused were apprehended from Lohardaga district late on Wednesday, and a car used by them was seized, an officer said.
The Rashtriya Swayamsevak Sangh (RSS) had alleged that petrol bombs were hurled at its office in the Nivaranpur area early on Wednesday, prompting the police to constitute a special investigation team to probe the matter.
"Two persons were arrested in connection with the case. They are being interrogated," Ranchi Senior Superintendent of Police (SSP) Rakesh Ranjan told PTI.
During the investigation, the police had recovered shards of glass bottles from the spot.
A forensic team visited the spot to ascertain the contents of the bottles, according to the police. The bomb detection and disposal squad also visited the RSS office.
The contents of the bottles are suspected to be petrol, another officer said, adding, "no explosive item such as an IED or bomb was found".
