The Palestinian Authority released on Thursday two West Bank leaders of the Islamic Jihad movement who were detained Wednesday in connection with a bombing that killed a British citizen in Jerusalem.

Khaled Jaradat and Tareq Qa'dan were detained for several hours but released due to lack of evidence, Qa'dan told Ma'an. He said that "there was no direct reason for the arrest."

Walid Badad, an official from the Islamic and national factions in Jenin, said the release came after a meeting in which factions "affirmed the prohibition against politically motivated arrests."

In Jerusalem, Israeli police were placed on high alert in the wake of the bomb blast near the central bus station on Wednesday, and will remain on alert in the coming days, officials told Israel Radio.

Israel's Police Commissioner Inspector-General Dudi Cohen reportedly gave orders to beef up the Jerusalem District Police and the Southern District Police presence throughout the regions.

An official told the radio that the bombing did not indicate the start of a new string of attacks, but that the event was nonetheless worrying. The official said authorities know who was behind the attack, though no group has claimed to have carried out the incident. Investigations were ongoing to locate the attackers, he said.

The bomb was inside a bag left near a West Jerusalem bus stop, Israel's internal security minister Yitzhak Aharonovitch told journalists at the scene. The blast went off as bus 74 stopped to pick up passengers at a stop near the central bus station and Jerusalem Conference Center. According to a statement from the Israeli military, two buses were hit with the explosion, which was named as a terrorist attack.