Different explosions can be when one incident sets of the next one
Yes, there are indications of sabotage, but I'll wait with my judgement. From your second link 'suggesting sabotage' 'believed by explosives', so far from proved.
I am open to any explanation. So far I have seen claims of sabotage but have not heard of any proof of that nor are there obvious suspects.
I don't think we can discard other explanations like lack of maintenance just yet.