Egyptian President Hosni Mubarak has ordered the opening of the Rafah border crossing to allow humanitarian aid into the Gaza Strip, the official MENA agency reported.
The order came a day after a deadly raid by Israeli commandos on an aid flotilla bound for Gaza, which has been under a crippling Israeli blockade since 2007.
"Egyptian President Hosni Mubarak has given orders to open the Rafah border crossing to allow humanitarian and medical aid into the Gaza Strip, as well as to receive medical cases which require access to Egyptian territory," MENA said.
"This comes as part of Egypt's moves to ease the suffering of the Palestinian people in the Gaza Strip."
According to Egyptian security sources in Rafah, the border opened on Tuesday at 1.30 pm (1030 GMT). No date has been set for it to close again.
The Rafah border is Gaza's only crossing that bypasses Israel. Egypt has kept it largely closed, opening it for humanitarian cases on two days a week.
A 2005 agreement brokered by the United States, put the Palestinian Authority and Israel in charge of the border, with observation from the European Union.
Egypt has come under harsh regional criticism for keeping the border closed and for building an underground wall in a bid to curb smuggling, which it views as a security risk.
Israel imposed its crippling blockade on Gaza in 2007 after the Islamist Hamas movement seized control of the territory from forces loyal to Western-backed Palestinian president Mahmud Abbas.
In December 2008, Israel launched a massive offensive in a bid to halt rocket and mortar fire by Gaza-based militants. About 1,400 Palestinians and 13 Israelis were killed during the 22-day conflict.
Since 2007, Gaza's 1.5 million people have relied on a web of tunnels beneath the Rafah border for most of their needs.
The World Bank estimates that 80 percent of Gaza's imports are brought in through the tunnels.
Most of the tunnels are used to bring in basic goods such as food, household appliances, building materials and livestock, but Hamas and other armed groups use their own more secret tunnels to smuggle in weapons and money.
The move to open the border came after Israeli commandos stormed an aid flotilla bound for Gaza on Monday, killing at least nine pro-Palestinian activists and sparking an international outcry.
The six ships were carrying some 10,000 tonnes of supplies.