Egypt has sealed the Rafah border crossing with the Gaza Strip in protest at the abduction of seven security personnel in Sinai.
Police on Friday locked the gates and placed barbed wire at the entrance.
Rafah is the only regular exit from Gaza for 1.6 million Palestinians living there. Other crossings into Israel are allowed only in exceptional cases.
The three policemen and four soldiers were captured while travelling in the peninsula, east of El Arish, on Thursday. Four of them reportedly worked at the Rafah crossing.
A BBC correspondent said there is a long queue of people in front of an Egyptian tank which is across the road outside the Egyptian gate.
Sinai has become increasingly lawless since President Hosni Mubarak was ousted in 2011.