Egyptian police fired warning shots in the air on the Gaza-Egypt border on Wednesday as Palestinians and Egyptians ignored a 6 pm (1500 GMT) deadline for returning to their own side of the border.
Thousands of people have travelled freely back and forth across the line since Israeli forces pulled out of the area on Tuesday. Egypt said it would impose controls once the Palestinians finish celebrating the end of Israel's presence.
A small contingent of about 20 Egyptian riot police arrived at the Salaheddin Gate in the divided town of Rafah on Wednesday and made an initial attempt to plug the gaps which civilians have made in the wire fence.
One of the policemen fired three shots over the heads of crowds trampling down another section of the fence. One policeman started to check the identity cards of people entering Egyptian territory but at other places nearby travellers continued to clamber over the obstacles, crossing the border without any formalities.
A brisk trade continued. Egyptians brought blankets from Gaza, while Gazans went home with snack food and livestock.
Several Palestinians were waiting to see Egyptian-based relatives for the first time in many years and were not in the mood to listen to orders from Egyptian police.
The Egyptian government says it is fully committed to an agreement with Israel on border controls but that under the exceptional circumstances of Tuesday it did not want Palestinians to see Egyptian troops as replacing Israelis.
TUNNEL FOUND Earlier on Wednesday, Egyptian border guards destroyed a tunnel to the Gaza Strip after finding guns and grenades in it, a reassuring action for Israel.
"The opening of a tunnel was found ... and it went to the other (Gaza) side of the border," an Egyptian security official, who asked not to be identified, told Reuters. He said it was discovered near the Rafah border crossing.
Israel says Palestinians have long smuggled arms from Egypt.
The tunnel, which started inside a house and was at least 10 metres (33 feet) below the surface, contained 35 automatic rifles with 115 magazines and three rocket-propelled grenade launchers with 280 grenades, the security official said.
He said no one was found in the tunnel or nearby, and the tunnel had since been destroyed.