Gaza,(Agencies) – US Senator John Kerry was given a letter for President Barack Obama believed to be from Hamas during his visit to the war-ravaged Gaza Strip ruled by the Islamist movement, a UN spokesman said on Friday.

“A letter addressed to Obama was left at the gate of our offices in Gaza; it is believed to be from Hamas,” said Christopher Gunness of UNRWA, the agency for Palestinian refugees.

Asked about the contents of the letter, Gunness said: “We are very polite at UNRWA, we don’t open other people’s mail.”

He said the letter was given to the influential senator when he met UN officials at the compound during his Gaza tour on yesterday.

Sen. John Kerry trip to the Gaza Strip is the first the highest-level visit by a U.S. official since the Hamas militant group seized power in the territory nearly two years ago.

Kerry did not meet with anyone from Hamas, which the U.S. shuns as a terrorist group, and used the visit to urge the group to end its violent campaign against Israel.

Transport and security were provided by the United Nations, and the senator had no contact with Hamas police at the checkpoints passed. An Associated Press reporter who covered the visit recognised no known Hamas officials among the local people met by Kerry.

However, the presence of the Massachusetts senator and former Democratic presidential nominee was a possible harbinger of a new U.S. approach in the region.

Since taking office last month, President Barack Obama has said he wants to improve America’s ties with the Muslim world. Kerry is considered close to Obama, and a separate visit to Gaza by Rep. Keith Ellison, the first Muslim congressman, was another possible sign of a new U.S. approach.

The White House had no comment on Kerry’s Gaza visit.

In Israel, legislator Yuval Steinitz, a member of the Hawkish Likud party on parliament’s Foreign Affairs and Defense Committee, said he saw no policy message in Kerry’s tour.

“I don’t think it means anything because Kerry is a member of the Senate and does not represent the administration. It’s just the United States saying it is not ignoring the Palestinians,” Steinitz said. “It’s not a change in policy because he didn’t meet with any Hamas members.”

Accompanied by U.N. escorts, Kerry said he was in Gaza to view the aftermath of Israel’s recent military offensive against Hamas. The operation killed some 1,300 Palestinians, including hundreds of civilians, caused widespread destruction and left thousands homeless.

“Let me make this clear, there is no change in policy,” said Kerry, who chairs the Senate Foreign Relations Committee. “I am here to listen with the U.N. personnel on the ground…. The things we need to do is to improve the situation in the region.”

Kerry toured the ruins of an American-style school that was destroyed in the Israeli bombing, and visited a neighborhood in northern Gaza where dozens of homes were flattened. He also spoke to residents, including Shaarhabel Alzeem, a prominent attorney.

“We highly appreciate your visit here and hope you can talk to your colleagues and say that we want peace with Israel. But we also need to live respectable lives,” Alzeem told the senator.

“Your political leadership needs to make it clear how it is willing to move to make peace and those decisions have not been made yet,” Kerry responded. “Your political leadership needs to understand that any nation that has rockets hitting it for many years threatening its residents is going to respond.”

Israel launched the offensive in response to years of Palestinian rocket attacks on its south. The sides declared separate cease-fires Jan. 18, but sporadic violence has persisted while Egypt works to broker a long-term truce.

Two other Democratic congressmen, Ellison and Rep. Brian Baird of Washington, also came to Gaza on Thursday. Like Kerry they met with no known Hamas officials.

During the day, Israeli warplanes attacked six suspected weapons-smuggling tunnels in southern Gaza in response to new rocket fire, the army said.

The airstrikes set off a huge explosion, signaling a weapons cache had been hit, the army said. The airstrikes took place about 20 miles (30 kilometers) from where the lawmakers were visiting; there were no reports of injuries.

Visits by U.S. officials to Gaza have been rare since Palestinian militants blew up an American diplomatic convoy in 2003, killing three people.

Before Thursday, no American officials had come to Gaza since Hamas won Palestinian elections in June 2006. The group violently seized control of Gaza the following year after a brief civil war.

Hamas official Ahmed Yousef welcomed the arrival of the Americans. “We highly appreciate the visit of any delegation that wants to find out the facts and see what has happened on the ground in Gaza,” he said.

Israeli government spokesman Mark Regev said Kerry met Prime Minister Ehud Olmert early Thursday, but made no mention of his plans to go to Gaza.

Kerry, a 2004 Democratic presidential candidate who now heads the Senate’s foreign relations committee, was scheduled to hold talks with Israeli President Shimon Peres on Friday.

He planned to fly on to Syria on Saturday as part of a regional tour.