About 55 people were injured late Tuesday in clashes between Egyptian police and pro-Palestinian activists trying to get a relief convoy into the Gaza Strip, militants and medics said.
Some 520 activists belonging to the convoy - led by charismatic and outspoken British MP George Galloway - broke down the gate at the port in El-Arish to protest an Egyptian decision to ship some of the goods through Israel.
They blocked the two entrances to the Sinai port with vehicles, and clashed with police. Forty were injured, a source close to them said, while medical sources said 15 policemen were also hurt.
The protests were sparked by an Egyptian decision to allow 139 vehicles to enter Gaza through the Rafah bordering crossing, about 45 kilometers (30 miles) from El-Arish, but requiring a remaining 59 vehicles to pass via Israel.
Talks in which Galloway and a delegation of Turkish MPs sought to change the Egyptian's minds proved unsuccessful.
Early Wednesday the activists were entrenched in the port surrounded by hundreds of police, an AFP correspondent said.
The convoy of nearly 200 vehicles arrived in the Mediterranean town on Monday after a dispute with Cairo on the route.
But the convoy's arrival came after a bitter dispute between its organizers and the government, which banned the convoy from entering Egypt's Sinai from Jordan by ferry, forcing it to drive north to the Syrian port of Lattakia.
Cairo accused the convoy organizers of trying to embarrass Egypt, which has refused to permanently open its Rafah border crossing with Gaza after the Islamist Hamas movement took control of the Palestinian enclave two years ago.
Israel and Egypt have severely restricted travel to and from the Gaza Strip since Hamas seized power there in June 2007, after winning Palestinian legislative elections in 2006.
Hamas's takeover of the impoverished and densely populated territory led to an Israeli blockade that allows in only very basic supplies. Gaza was devastated in a war last winter between Hamas and Israel.