GAZA CITY (AFP) - Palestinian group Hamas on Saturday denied that three of its activists killed in a Gaza air strike were plotting to kidnap Israelis and warned of "consequences". The Israeli air force launched a missile in the early hours of Saturday at a car travelling in the southern Gaza Strip, killing three members of the Hamas armed wing and wounding a fourth person. An Israeli military spokesman said the raid, planned jointly with the Shin Bet domestic security agency, was a preemptive strike against militants planning to kidnap Israelis during the coming Jewish festival of Passover. "An Israel air force aircraft hit a Hamas terror cell... planning to carry out kidnapping attacks in the Sinai peninsula and in Israel during the Passover holiday," he told AFP. The Sinai coast of neighbouring Egypt is a popular destination for Israelis during the week-long holiday, which begins on April 18 and commemorates the biblical exodus of the Israelites from Egypt, despite repeated government warnings of the danger of attack. Israeli public opinion is still inflamed by the capture by Gaza-based militants of conscript Gilad Shalit in a deadly cross-border raid in 2006. Shalit is still missing, believed held somewhere in the Gaza Strip. Hamas said in a statement that the three dead were members of the group's Ezzedine al-Qassam Brigades and identified them as Ismail Lubbad, Abdullah Lubbad and Mohammed al-Dayah. The three were to be buried later on Saturday. The air strike was a "serious escalation" and Israel "will bear all the consequences", the Brigades warned. A later statement from Brigades spokesman Abu Obeida called the kidnapping allegation "nonsense" and warned of retribution. "If the enemy wants to play with fire, it will get burned by fire," Abu Obeida said. The group added that one of the dead men, Ismail Lubbad, had previously been a bodyguard for Hamas leader Abdelaziz Rantissi, assassinated in a 2004 Israeli air strike in Gaza City. On Wednesday, an Israeli strike on southern Gaza killed a militant from radical group Islamic Jihad and wounded another, but generally the past few days have seen a return to relative calm after a spate of Palestinian rocket attacks into Israel and Israeli counterstrikes. The spate of tit-for-tat violence began on March 16 when a rocket fired from Gaza landed in an open area of southern Israel, without causing casualties or damage. Within hours, the Israeli air force hit back, killing two militants from the Ezzedine al-Qassam Brigades, in what some saw as a disproportionate response. Two days later, Hamas militants responded, firing a barrage of around 50 mortar rounds at the southern Israeli city of Beersheva in the fiercest bombardment in two years. On Sunday, the Israeli military made a trial deployment outside Beersheva of the first batteries of its "Iron Dome" short-range missile defence system. Despite the spike in tensions, both Israel and Hamas have shown reluctance to be dragged into another bloody confrontation like their December 2008-January 2009 war, which killed more than 1,400 people, the vast majority of them Palestinians.