STOCKHOLM - Swedish Foreign Minister Margot Wallstrom called on Tuesday for an investigation to determine if Israel was guilty of extrajudicial killings of Palestinians during the recent wave of violence there, local media reported.The comments were the latest in a series of statements by Wallstrom that have irked Israeli authorities. Ties between Sweden and Israel nose-dived after Sweden announced its recognition of a Palestinian state shortly after Wallstrom's center-left Social Democrats won general elections in 2014.She deepened the rift last year by describing Palestinians' plight as a factor leading to Islamist radicalization."It is vital that there is a thorough, credible investigation into these deaths in order to clarify and bring about possible accountability," Wallstrom said during a parliamentary debate, according to news agency TT .Rights groups have accused Israel of using excessive force to quell the unrest.The United States, the European Union and the United Nations have all expressed concern, saying that while they recognize Israel's right to self-defense, restraint is necessary to ensure the violence does not escalate further.Almost daily stabbings, car-rammings and shootings by Palestinian attackers have killed 21 Israelis and a US citizen since early October, raising fears of a wider escalation a decade after the last Palestinian Intifada subsided.Israeli forces or armed civilians have killed at least 133 Palestinians in the same period, 83 of whom authorities described as assailants. Most of the others have been killed in clashes with security forces.Science, Technology and Space Minister Ofir Akunis responded to the the Swedish foreign minister's claims against Israel, saying an investigation should be conducted instead on "how a woman who so bluntly hates Israel was elected, and still holds the role of foreign minister of Sweden."Also on Tuesday, the Foreign Ministry of Israel released a statement addressing the Swedish FM's claims, saying that the Wallstrom's comments were "irresponsible and surreal, and gives support to terror and encourages violence."