JERUSALEM, March 18 (Reuters) - Palestinian militants fired a rocket into Israel
from the Gaza
on Thursday, killing a Thai agricultural worker, while the European Union's foreign affairs chief was visiting the Hamas
It was the first strike from the territory to cause any fatalities since the end in January 2009 of Israel's Gaza war.
An hour before the attack, the EU's top diplomat, Briton Catherine Ashton, crossed into the Gaza Strip to tour U.N. facilities and see how the international funding was being used.
An unknown Gaza group, Ansar al-Sunna, claimed responsibility for the attack, launched a day before the international Quartet of Middle East peace mediators was to meet in Moscow to discuss ways to revive Israeli-Palestinian talks.
Similar strikes since the Gaza war have been met by Israeli air raids against militants or suspected weapons-producing facilities, but the death of the Thai worker, in Netiv Ha'asara, an agricultural community, may harden Israel's response.
This is a crossing of the red line, which Israel cannot accept. The Israeli response will be appropriate. It will be strong, Vice Prime Minister Silvan Shalom told reporters.
The incident, however, could have more of an impact on internal Palestinian politics than on the Middle East peace process, which Hamas has refused to join.
Hamas Islamists, who seized the Gaza Strip in 2007 in fighting with forces loyal to Palestinian President Mahmoud Abbas, had been urging other militant groups not to mount attacks on Israel, voicing concern about retaliation.
But it has been faced with a mounting security challenge -- including bombings against Hamas officials and facilities -- by Palestinian militant groups sharing the more hardline Islamist ideology of al Qaeda.
A known figure in the hardline Salafist movement, whose agenda of jihad, or holy war, against the West is contrary to Hamas's nationalist goals, said Ansar al-Sunna was a newly established group sharing al Qaeda ideology.
The Jihadist mission came in response to the Zionist assaults against the Ibrahimi and al-Aqsa mosques and the continued Zionist aggression against our people in Jerusalem, Ansar al-Sunna said in a statement.
It appeared to be referring to Israel's national heritage plan to renovate holy sites, including the West Bank town of Hebron's Tomb of the Patriarchs that is revered by Muslims and Jews, and the rededication this week of an 18th-century synagogue in Jerusalem, some 400 metres (yards) from al-Aqsa.
In a statement on the rocket attack, Hamas steered clear of comments that could be seen by Palestinians in the Israeli-blockaded Gaza Strip as disapproving of a strike against its enemy, even while the strike strained an informal truce.
The government of the Zionist enemy, which has launched a war against the Palestinian people and against holy sites and al-Aqsa mosque, bears the responsibility for all the escalation, Hamas spokesman Fawzi Barhoum said.
At Hamas's urging, Palestinians in the occupied West Bank and East Jerusalem mounted stone-throwing protests this week after Israel reconsecrated the Hurva synagogue in Jerusalem's walled Old City.
Palestinian militants in Gaza have been carrying out sporadic rocket and mortar bomb attacks on Israel since the end of the December 2008-January 2009 Gaza war, usually without causing any casualties.
The number of such strikes has dropped dramatically since the Israeli campaign ended.
More than 1,400 Palestinians, including hundreds of civilians, were killed in the three-week offensive that was launched with the declared aim of curbing rocket attacks. Thirteen Israelis, among them three civilians, were killed.
In the most serious violence to date between Hamas and the Salafis, Hamas forces attacked a mosque in Rafah last August after the leader of a group calling itself Jund Ansar Allah declared Islamic rule in the town on the border with Egypt.
Up to 28 people, including the leader, were killed.
Since then, Salafi groups have accused Hamas of trying to block them from firing rockets into Israel. (Writing by Jeffrey Heller; Additional reporting by Nidal al-Mughragbi; Editing by Louise Ireland)