By Nidal al-Mughrabi

GAZA, July 1 (Reuters) - Israel shut its border crossings with the Gaza Strip on Tuesday in what it called a response to a rocket attack a day earlier that further strained a ceasefire.

Sami Abu Zuhri, a Hamas official, denied any rockets had been launched on Monday from the territory, which is under the control of the Islamist group.

In fresh violence, Israeli forces guarding the Sufa crossing into the southern Gaza Strip shot and wounded a Palestinian woman, Palestinian medical officials said. An Israeli military spokesman said the army was not aware of a shooting incident in the area.

"All the crossings are closed, except for the Erez crossing, which is open for humanitarian use only," said Shlomo Dror, an Israeli Defence Ministry spokesman.

"We had given an order to increase the number of trucks from 60 to 90 per day, but the other side continues to fire (at Israel)," he said, referring to goods that were to have been transferred to the Gaza Strip.

He gave no timeframe for reopening Gaza crossings.

An Egyptian-brokered ceasefire between Israel and Hamas went into effect on June 19. Abu Zuhri said all Palestinian factions were committed to what he termed "calm".

Israel had previously shut the crossings on June 25 after Islamic Jihad launched a cross-border rocket attack in what the militant group described as a response to the killing by Israeli forces of one of its leaders in the occupied West Bank.

The West Bank is not covered by the ceasefire, but Islamic Jihad had put Israel on notice that it might react violently to raids in the territory. Israel says its military operations in the West Bank help to prevent attacks on Israelis.

Other Gaza militants have also fired a rocket and two mortar bombs in separate incidents since the truce took effect. U.N. sources said last week Israeli forces opened fire in the Gaza Strip at least eight times, wounding two people, after the ceasefire began.

Israel sharply cut back the supply of goods into the Gaza Strip a year ago, after Hamas seized the territory from forces loyal to President Mahmoud Abbas's more secular Fatah faction.

Along its border with the Gaza Strip, Egypt opened the Rafah crossing on Tuesday for three days for the limited passage of people, such as Palestinians stranded in Egypt and Gazans seeking medical treatment abroad. (Writing by Avida Landau, Editing by Richard Balmforth)

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