Some 150 people from sub-Saharan countries attempted the crossing at 7.30 a.m. Tuesday but police stopped many from entering the territory, the Spanish news agency Efe and other media outlets said.
Comment from government offices in Melilla was not immediately possible.
Melilla and nearby Ceuta are two tiny Spanish coastal territories in northern Africa separated from Morocco by tall wire fences that are constantly monitored by police.
Efe said the crossing attempt was the biggest since last August when some 300 people tried but only 30 got across.
Separately, the Interior Ministry reported this week that migrant arrivals to Spain’s Canary Islands, one of the principal migrant routes from Africa, were up by more than 230% to 1,069 in the first two weeks of the year.
More than 23,000 people reached the islands by boat from Africa last year.
Some 2,250 people entered Ceuta and Melilla in 2020, according to ministry figures.