Sweden cannot sue Israel for raids against two ships manned by radical activists attempting to break its naval blockade on Gaza, prosecutors said Tuesday.
Acting on behalf of Swedes on board two separate vessels, in 2010 and 2012, the Swedish Prosecution Authority launched a probe in June.
"After hearing the Swedish plaintiffs we have identified some facts that may constitute offences, but the perpetrators are unknown and we are unable to determine their identity," prosecutor Henrik Attorps said in a statement.
Israel, whose relations with Sweden have cooled since Stockholm recognized the "state of Palestine" on October 30, has not cooperated with the prosecution inquiry.
The probe follows a first 2010 raid by Israeli troops on a six-ship flotilla. On one of the ships, the Mavi Marmara, troops were attacked by Turkish Islamist from the Al Qaeda-linked IHH organization, and opened fire - killing nine militant Islamists. The ship was later revealed to have been carrying no "humanitarian aid" whatsoever, despite claims to the contrary.
In 2012, Israel's navy seized another ship, the Estelle, a Finnish-flagged galley carrying humanitarian aid as part of the international Ship to Gaza campaign.
The people on board, including the Swedes, were allegedly held against their will in Israel following the boarding.
"We have no jurisdiction over acts committed on Israeli territory," Attorps said in the statement.
The prosecutors investigated the cases, including claims of "aggravated assault", with reference to the Geneva Conventions, which says civilians must be protected during armed conflicts.
Gaza has been under an Israeli blockade since 2006 and was tightened in 2007 after the Islamist terrorist group Hamas seized control, as part of efforts to stop the terror group's rocket attacks against Israeli civilians. The blockade, which was ruled legal by a UN probe, has eased considerably in recent years due to international pressure.
Israel recalled its ambassador after Sweden's October 30 recognition of the "state of Palestine," in a purely symbolic move, but a month later allowed his return.