A transport workers strike as kept Gaza's Kerem Shalom crossing for a fifth day Thursday, as truck drivers take the wheel of a protest demanding an end to the closure of Gaza's only bulk goods crossing, announced the week before.

The strikers were demanding that the PA retract its agreement on the closure of the bulk goods crossing, saying the new arrangements would mean not only a reduced flow of goods into Gaza, but also increased risk to drivers making the trek from the southenmost tip of Gaza to the northern population center of Gaza City over what drivers say are dangerous roads.

Israel's military said that projectile attacks on military targets near the Karni crossing led to its closure, but said that despite the reduced number of operating crossings - from two down to one - the goods expected to enter Gaza would increase four fold.

A report from Oxfam International, released on Thursday, said the permanent closure of Karni "is already affecting the Gaza Strip with longer waits for the entry of commercial and humanitarian goods and increased transport and labor costs."

The secretary of the transport workers union Jihad Islim said the Gaza government had already asked that strikers disassemble their protest tent and resume work, but the union has refused.

"We are demanding the formation of a commission of inquiry, we want to know the real reasons for the closure of the Karni crossing," he said.

Israeli rights group Gisha called "Limiting access to a small crossing near the Egyptian border is consistent with a series of steps aimed at cutting Gaza off from Israel and the West Bank."

On Tuesday night, Israeli crossings officials unexpectedly opened the long-closed Sufa crossing, allowing the transport of 500 tons of construction materials though, and advising UNRWA - which has been waiting for the materials since 2007 - to pick up the goods Wednesday morning.

UNRWA officials said Wednesday that the opening was likely a "test," and hoped the crossing would be used to transport into Gaza the 72,000 tons of materials that have been purchased by aid groups for reconstruction projects and are waiting on the Israeli side of the crossings.

The aid group's spokesman in Gaza could not be reached Thursday to confirm whether the crossing was again opened.