In this task, given a sentence in the English language, your task is to convert it into the Japanese language.
One example is below.
Q: Test subjects will be administered either a placebo or PA-457 that will be taken in combination with the medication they already take.
A: 被験者は、彼らがすでに服用している薬剤と一緒に偽薬またはPA-457を与えられる。
Rationale: The above sentence is correctly translated from English to Japanese.
Q: The cause of death has been reported to be an explosion, but the source is unclear.
A:
死亡原因は爆発によるものと報告されたが爆発物は不明である。