Iran has played a key role in helping the militant Palestinian group Hamas to develop the deadly weapons arsenal that has allowed it to hit targets deep inside Israel, according to Western intelligence officials. Senior Hamas commanders are believed to have made regular visits to Iran, where they have undergone training in the production and operation of sophisticated weapons systems, as well as inspecting rocket production facilities controlled by the Islamic Revolutionary Guard Corps (IRGC). The IRGC’s elite Quds Force - which translates as 'Jerusalem Force' - has responsibility for Iran’s dealings with Hamas. Qassim Soleimani, the unit’s late commander, took personal charge of overseeing Hamas’s arms build-up until he was killed in a drone strike authorised by Donald Trump, the former US president, last January. Intelligence officials believe the technological assistance provided by Iran, which includes detailed advice on setting up Hamas’s own production infrastructure in Gaza, has resulted in a significant improvement in the terrorist organisation’s ability to strike targets deep within Israel. In the past few days Hamas rockets have struck major Israeli cities and towns such as Tel Aviv and Lod, and enabled Hamas to focus on particular targets, such as the country’s main Ben Gurion airport, prompting a number of major airline carriers to cancel flights as a security precaution.