Islamist militia linked to Iran have continued to strike US bases in Syria and Iraq, intensifying a campaign of violence that will raise fears of a regional conflagration. The attacks have been claimed by groups either directly controlled by Tehran or sharing the ideology of other groups currently fighting Israel. On Thursday, a US base at Kharab al-Jir in Syria was attacked for the second time in two days, and a base in western Iraq was also hit. More than a dozen small-scale strikes on US bases in the region have wounded 24 US soldiers and caused the death of one civilian contractor. Washington is rushing anti-missile batteries to the region to protect its principal bases and allies. Charles Lister, the director of the Syria and countering terrorism and extremism programmes at the Middle East Institute in Washington, said: “The US has now had two dozen soldiers injured. In any other conditions it would have responded but its hands are tied because it does not want to be blamed for escalating. The US government is very concerned that we are walking into a regional crisis. “The attacks show that Iran has an extensive network of well-armed, aggressive and well-coordinated proxies across the region which it has established for exactly this scenario. They are currently testing redlines but not pushing too hard. They are putting the onus on the US to respond.” Joe Biden has already ordered two aircraft carriers to the eastern Mediterranean and US officials are reported to have asked Israel to hold off on a ground invasion of Gaza until new anti-missile units have reached their destinations. The war between Israel and Hamas has followed the terrorist attacks launched by Hamas into southern Israel, which killed 1,400 people, mainly civilians. So far Israel’s bombardment of Gaza has killed 7,000, according to Hamas-run health authorities in the enclave. Even without a ground offensive by Israeli troops into Gaza, the rising death toll there is likely to bring further escalation. One Iraq-based and Iran-supported group, believed to be a front for the long-established Kateb Hezbollah, last week issued a statement threatening attacks on US military bases in the UAE and Kuwait. Paramilitaries from militia in Syria that are controlled by Iran have been deployed close to the Golan Heights, in a further threatening move. On Wednesday, leading officials of the three principal Islamist extremist groups currently at war with Israel met in Beirut to discuss the conflict. After the meeting in Lebanon, a brief statement said Hezbollah’s leader, Hassan Nasrallah, had agreed with Hamas’s Saleh al-Arouri and Palestine Islamic Jihad’s leader, Ziad al-Nakhleh, that the three – along with other Iran-backed militants – wanted to achieve “a real victory for the resistance in Gaza and Palestine” and halt Israel’s “treacherous and brutal aggression against our oppressed and steadfast people in Gaza and the West Bank”. Tobias Borck, a senior research fellow in Middle East security studies at London’s Royal United Services Institute, said Iran was “literally playing with fire”. “What we are seeing is the next level out from the Gazan war. This is all carefully calibrated to show solidarity. Iran is saying: we see the aircraft carriers but we are not scared and we can hurt you too. It is incredibly dangerous,” Borck told the Guardian. “A lot of people want to understand it as Tehran pulling the strings but … actually these are partners who share a worldview and ideology. One element is claiming the mantle of leading the opposition to a western-imposed order in the region.” The impression of a growing regional conflict was reinforced by Israeli airstrikes against Syrian army infrastructure in response to rockets launched from Syria, an ally of Iran, last week. Syria’s state news agency said the attack near the south-western city of Daraa killed eight soldiers. The strike followed the launch of two rockets that set off air raid sirens in the Israeli-occupied Golan Heights. Israeli warplanes also bombed an airport in Aleppo, in northern Syria, in a move that experts said was probably intended to disrupt supplies of ammunition and arms from Iran to Hezbollah in Syria. Hezbollah has been exchanging fire with Israeli troops along the border between Lebanon and Israel since the day after the 7 October attacks. Both sides appear to have be trying to avoid escalation. An estimated 40 Hezbollah fighters have been killed in the clashes so far, while the Israeli military has also announced some deaths among its ranks. Israeli officials have said they would retaliate aggressively in the case of a cross-border attack by Hezbollah from Lebanon, but fear the organisation’s arsenal of about 150,000 rockets and missiles. Both sides are trying to pre-empt any blame for further and greater hostilities. The White House said on Monday that the US had detected “an uptick in rocket and drone attacks by Iranian-backed proxy groups against military bases housing US personnel in Iraq and Syria” and was “deeply concerned about the potential for any significant escalation of these attacks in the days ahead”. Last week a US warship in the northern Red Sea intercepted missiles fired by Iran-backed Houthi rebels from Yemen, possibly at Israel.