The blast caused no injuries but sent Gazans rushing to the open crossing.
Hamas gunmen rushed to the scene to prevent anyone from crossing the border, and there were no immediate crossings reported.
Several Palestinian groups had issued threats in recent days about attacking the wall, to allow Palestinians out of Gaza and allow others stranded in the Sinai peninsula to enter the Strip.
Hamas confirmed two explosions took place but denied any hole was created in the wall between Gaza and Egypt.
Meanwhile Egyptian officials ruled out any possibility for Fatah and Hamas to resume talks soon, the state-owned news agency said Tuesday as Egyptian security forces deployed reinforcements along the border with the Gaza Strip.
The Egyptian comments came after a delegation representing Palestinian President Mahmoud Abbas visited Cairo to coordinate how Egypt and Abbas' government would deal with Hamas after the militant movement seized the Gaza Strip last month.
"The current climate in the Palestinian arena does not permit resumption of the dialogue between Fatah and Hamas now," state-owned Middle East News Agency quoted an unidentified Egyptian official as saying.
Meanwhile, hundreds of Egyptian police and security forces were deployed in reinforcement along the border with Gaza late Tuesday, geared at preventing Palestinian infiltration to and from Gaza Security officials told AP.
Egypt rules out reopening its border crossing with Gaza any time soon, the official MENA news agency also reported Tuesday.
MENA quoted Egyptian Foreign Minister Ahmed Aboul Gheit as saying that "those Palestinians who want to cross should use Kerem Shalom," referring to an Israeli-controlled border point.
The remarks seem to indicate a toughening of Egypt's position against the radical Islamic Hamas movement that imposed it rule over Gaza.
Some 4,000 Palestinians have been stranded in Egypt's Sinai Peninsula since the Egypt-Gaza border crossing was closed in early June. Fatah supports an Israeli proposal to reroute the stranded travelers through Kerem Shalom but Hamas rejects the idea.