Qatar emir in landmark visit to Gaza RAFAH, Gaza Strip, Oct 23 - The Emir of Qatar entered the Gaza Strip on Tuesday for a visit that broke the isolation of it Islamist rulers, Hamas, but disappointed Israel and mainstream Palestinian leaders in the West Bank. Sheik Hamad bin Khalifa al-Thani crossed into Gaza from Egypt at the head of a large delegation on what is billed as a humanitarian visit to inaugurate $250m worth of reconstruction projects. It was the first trip by a head of state to Gaza since 1999 and the emir was given a red-carpet welcome by Ismail Haniyeh, the Hamas prime minister, who declared it a historic day for the enclave, which backs on to the Mediterranean sea. The western-backed Palestinian Authority of President Mahmoud Abbas, Hamas's arch-rival, said it hoped the visit would not undermine efforts to rebuild Palestinian unity or signal approval for a separate Palestinian territory. An Israeli foreign ministry spokesman said it was "astounding" that Qatar was taking sides, noting that the emir "has never dignified the PA with a visit." Hamas seized control of the enclave in 2007 after a brief battle with the armed wing of Mr Abbas's Fatah movement. It refuses to renounce violence or to recognise Israel's right to exist and it is ostracised by the west as a terrorist organisation. Mr Haniyeh denies Hamas is seeking to create its own state in the tiny enclave, which is under partial blockade by Israel, with Egypt helping to enforce the Jewish state's restrictions. The emir and his large delegation were greeted by a Hamas honour guard and Palestinian and Qatari flags decorated the route on the main road north to the city of Gaza, a key highway that Qatar will rebuild. His visit coincided with another round in the low-level conflict between Israel and Hamas. An Israeli officer was badly injured by an explosion on the Gaza border and Benjamin Netanyahu, Israel's prime minister, promised a "strong response," which often comes in the form of Israeli air strikes. The emir was due to make a public appearance in one of Gaza's largest soccer stadiums, and security arrangements have been in place for days ahead of the visit, seen by Hamas as a victory after five years of isolation. Western-allied Gulf Arab states are trying to lure Hamas away from its alliance with Iran, whose nuclear energy programme has raised the prospect of a war with Israel. Qatar's emir has met Israeli leaders in the past and is working hard to boost the diplomatic clout of his small country. He has also previously sought to mediate between Hamas and Fatah to end the divisions that have weakened the Palestinian cause. Hamas says his trip would mark the beginning of the end of Israel's blockade policy.