German Defense Minister Peter Struck said Monday that he had no reason to believe the weekend blast in northern Afghanistan that killed two German soldiers and five Afghans was an attack. "There are no indications of an attack and we continue to assume it was an accident," Struck said following the explosion Saturday of a stock of munitions at Rustaq, 120 kilometers (75 miles) northeast of Kunduz. He said a team investigating the incident was to deliver a report by the end of the week. The dead soldiers were part of an International Security Assistance Force (ISAF) contingent observing ammunition-sorting operations near the airfield at Rustaq, ISAF said. An Afghan translator and another German army soldier were also wounded in the blast in which two trucks transporting ammunition exploded. The police chief of the northern province of Kunduz, General Mutalib Bek, said Sunday that the explosion was caused by an electrical spark in the truck. Germany, with about 2,000 troops, is the biggest single contributor to ISAF, which has a total of 8,300 soldiers from 37 countries.