Q&A: What has changed in Israel's blockade of Gaza?

(Reuters) - Israel announced Sunday new steps to ease a land blockade of the Gaza Strip, after weeks of international pressure over an Israeli commando raid on an aid flotilla that killed nine pro-Palestinian activists.

Following are some questions and answers about the blockade.

HOW MANY PALESTINIANS LIVE IN GAZA?

There are 1.5 million people, of whom about 1 million depend to some extent on regular supplies of U.N. and other foreign aid brought in overland after Israeli inspection. The strip is a long rectangle roughly 40 km by 10 km (25 by 6.25 miles), along the Mediterranean coast, bordered by Israel to the north and east and by Egypt to the south. It is densely populated.

WHY IS GAZA UNDER BLOCKADE?

Because it is under the control of the militant Islamist movement Hamas, which does not accept Israel's right to exist and remains committed to armed resistance. The blockade was conceived over three years ago as a way of suffocating popular support for Hamas, but the strategy has not worked. Hamas remains firmly in power and the blockade is denounced by critics -- and increasingly abandoned by former Western backers -- as a form of collective punishment.

WHO DECIDES WHAT GETS IN AND OUT OF THE ENCLAVE?

Israel alone decides on what is openly allowed to cross the closed borders of the Gaza Strip. Most commercial goods have been banned throughout the blockade. Humanitarian aid is allowed in, subject to Israeli control. Gaza smugglers have dug hundreds of underground tunnels to Egypt on the southern border where contraband of all sorts, including weapons according to Israel, is smuggled in.

SO WHAT'S THE SUPPLY PROBLEM?

The United Nations aid agency charged with supporting Palestinian refugees (UNRWA) says people with power and money in Gaza can obtain "anything they want" via the tunnels. "There are lots of things to buy. But this stuff is out of reach of the abject poor," says spokesman Chris Gunness. The number of Gazans unable to afford sufficient food has risen threefold in the past year to 300,000. Gunness says it remains to be seen what the blockade changes will mean in practice.

WHAT HAS ISRAEL ADDED TO ITS LIST OF ALLOWED IMPORTS?

The new rules will replace a policy that banned everything Israel chose not to let in by a more transparent regime aimed at barring any transfer of items considered of military use. Israeli Prime Minister Benjamin Netanyahu said all goods would be allowed into Gaza except for weapons and materials that could be used to make them. A statement issued by his office said Israel would ban the import of construction materials that could be used by Hamas to make weapons or to restore its military facilities.

HOW DID HAMAS RESPOND TO ISRAEL'S ANNOUNCEMENT?

Hamas official Ismail Radwan rejected the new provisions.

"Hamas rejects this decision. This is an attempt to sap international anger over the blockade on the Gaza Strip," he told Reuters by phone from Gaza. He repeated his group's call for a complete end to the "siege," including a sea blockade

The United Nations also demands the lifting of the blockade, which it says is illegal.

WHY WAS ISRAEL RELUCTANT TO END BAN ON BUILDING MATERIALS?

Israel says unrestricted transfer of steel and cement and possibly weapons is a clear security risk. These materials could be seized by Islamist militants to build up their military infrastructure, replacing bunkers, reinforced firing positions and rocket launch sites. But cement and steel reinforcement rods are considered vital for the reconstruction of homes and factories destroyed in Israel's 3-week military offensive against Gaza from December 2008 to January 2009, which it launched with the declared intent of ending persistent rocket attacks by Hamas and other groups.

WHAT ABOUT ISRAEL'S BLOCKADE OF THE GAZA COAST?

This is the very last place Israel is likely to relax its grip on. Ships can transport big quantities of heavy weapons, such as the longer-range rockets that Israel says Hamas sponsor Iran has already tried to smuggle into the enclave. Israel is expecting more "blockade busting" aid flotillas in the coming days and weeks and has served notice that it will block them.

(Reporting by Douglas Hamilton and Nidal al-Mughrabi in Gaza; editing by Mark Trevelyan)