GAZA CITY, Gaza Strip (AP) — Egypt’s tight closure on neighboring Gaza after a weekend attack by Islamic terrorists has sent Gaza prices for construction materials soaring and left hundreds of medical patients stranded, officials said Wednesday.

The attack that killed 16 Egyptian soldiers at a Sinai Peninsula border post near Gaza also strained relations between Egypt’s new government and Gaza’s Hamas rulers. Hamas and Egyptian President Mohammed Morsi come from the region-wide Muslim Brotherhood, but Sunday’s attack, the worst ever by terrorists against Egyptian troops, drove a wedge between them.

In response to the attack, Egypt shut down the Rafah passenger crossing between Egypt and Gaza, as well as hundreds of smuggling tunnels under the border. Smuggling under the 15-kilometer (9-mile) border has circumvented official crossings and bypassed restrictions for many years.

Israel, which controls all other gates into Gaza, restricts the influx of goods into the territory, so Gazans smuggle in construction materials, cars and fuel. Israel charges that Hamas also receives weapons and cash through the illegal tunnels. Hamas officials are known to collect fees from tunnel operators.

Yasser Othman, the Egyptian ambassador to the West Bank-based Palestinian Authority, said Wednesday that the closure would remain in place until security is restored.

He rejected allegations by a senior Hamas official that the closure amounted to collective punishment, saying it was temporary and did not contradict pledges by the Morsi government to help Gaza in the long run.

Terrorists launched the attack on an Egyptian army camp near the point where Egypt, Gaza and Israel converge. Egyptian officials have said the assailants, believed to be Sinai militants with loose links to al-Qaida, had help from Gaza. The attackers stole Egyptian armored vehicles and crashed through the crossing into Israel, where they were apparently planning an attack, but Israeli forces stopped them.

Hamas has promised to cooperate with Egypt’s investigation but denied anyone from Gaza was involved.

Gaza, which is home to 1.7 million people, has lived with border restrictions by Israel and Egypt since the Hamas takeover of the territory in 2007.

Merchants and smugglers said Wednesday the tunnel closure immediately drove up the price of construction material, including cement and gravel, by 40-60 percent.

Merchants said Gaza has only 10 days’ worth of construction material in storage. If the tunnels remain closed for an extended period, some 17,000 Palestinians employed in construction could be put out of work, said Palestinian economist Omar Shaban.

Gaza Health Ministry spokesman Ashraf al-Kidra said several hundred Palestinian patients are waiting to cross into Egypt to get medical treatment there or in third countries.

“If the Rafah crossing is closed for more than a week, this will lead to a humanitarian crisis and increase the suffering of the sick,” he said.