Kenya's security minister says investigators think a recent explosion that killed two and injured 45 was not the work of terrorists.
George Saitoti told Parliament on Tuesday that preliminary investigations found a leaking petrol tank may have caused Sunday's explosion in a highly populated part of downtown Nairobi.
He said bomb experts found no evidence of an explosive device.
Kenya has been on high alert since the killing of Osama bin Laden because of threats from al-Qaida-linked al-Shabab militants in neighboring Somalia.
The group has threatened to attack Kenya for allegedly helping Somali government troops and their allies attack the militants' bases in Somalia.