Lorries were briefly prevented from crossing into Melilla overnight on Tuesday.
On Wednesday, no fish, fruit or vegetables came in as drivers apparently bowed to protesters' demands and did not make deliveries.
Kaddur said the demonstrations were only hurting the enclave, as well as Moroccans who live nearby and depend on the area for their livelihoods.
Morocco has made five complaints over the past month alleging Spanish police mistreatment of Moroccans, and also accused the Spanish coast guard of finding and then abandoning a group of ailing boat migrants off the coast.
The Spanish government has denied the claims.
The protesters have also used the border dispute to press Morocco's long-standing claim that Spain should cede control of Melilla and Ceuta, another Spanish enclave further to the west.
Spain rejects any talk of giving them up.
Many in Melilla and Spain suggest that the protesters had at least tacit support from the government of Morocco because Moroccan police did nothing to stop Wednesday's blockade and another one a week ago.
Spain and Morocco are key allies, co-operating closely on security threats and preventing illegal immigration.
But the dispute has led Spain's main opposition party to accuse the ruling Socialist Party of failing to reduce tensions.
Melilla depends on Morocco for shipments of perishable products and construction materials like bricks and gravel.
About 35,000 Moroccans cross daily into the enclave to work or shop.
Relations between Spain and Morocco had their most serious test in 2002, when a handful of Moroccan soldiers occupied a nearby rocky Spanish island inhabited by goats.
Jose Maria Aznar, Spain conservative prime minister at the time, sent in commandos to eject the Moroccan troops and it took US involvement to negotiate an end to the dispute.
On Wednesday, Aznar unexpectedly flew to Melilla as his Popular Party, now in opposition, accused the ruling Socialist Party of bungling efforts to reduce tensions and end the Melilla blockades.
Aznar said that the enclave and its residents were victims of "harassment and government neglect".
The Spanish government said Aznar's visit could hurt the delicate situation.
Spain's interior minister will visit Rabat, the Moroccan capital, on Monday in an effort to repair relations and discuss issues such as terrorism and immigration.
The government is "working on the problem, and it will be sorted out very soon, despite the Popular Party," Jose Blanco, the Spanish development minister, said.