A well-known leader in the Lebanese Shiite militant group Hezbollah was assassinated on Wednesday.

Hassan al-Laqis was shot and killed at close range while parking his car close to his apartment near south Beirut in Lebanon, the New York Times reports. He had been a key member of the group since its beginning three decades ago and had survived numerous assassination attempts. The killing was described as “professional-style” by the Times, which discussed the growing number of attacks on Hezbollah ever since the group has taken root in Syria in support of the actions of President Bashar al-Assad.

According to analysts, the death of al-Laqis was a major loss for Hezbollah. He has been linked to running the group’s extensive telecommunications network as well as working to attain strategic weapons, according to the Times.

Though Hezbollah did not reveal how al-Laqis was killed, it did blame “the Israeli enemy” of targeting him and said Israel would have to “bear all the responsibility and ramifications of this vile crime.” But it is believed that any of Hezbollah’s enemies could have wanted al-Laqis killed, including Syrian insurgents currently fighting the group or the Saudi Arabian or Lebanese Sunni militants supporting the insurgents.