The cargo included 220 short-range missiles and 50 improved long-range Fajar-5 rockets, intelligence sources told DEBKAfile, a Jerusalem-based military intelligence website.
The Fajar-5s have a 200-kilo warhead, the site said.
DEBKAfile said sources report four big Sudanese shipping boats sailed out of Port Sudan early Monday and are waiting to rendezvous with the freighter Cargo Star and offload its missile cargo at sea. Tehran would then tell the Sudanese the route to take to the Sinai coast, and the missiles would be smuggled through tunnels into Gaza, the report said.
Meanwhile, Israeli forces have killed more than 100 Palestinians during the six-day conflict in Gaza, Palestinians said Monday.
The Ma'an News Agency reported an Israeli airstrike injured eight civilians, two seriously, in the bombing of a family home in Jabaliya refugee camp in northern Gaza. A physically disabled man, Muhammad Zeidan, was killed in an airstrike on an agricultural area near al-Nuseirat.
Israeli planes also bombed a tower block housing several international media offices in Gaza for the second day, Ma'an said, killing a military leader of Islamic Jihad and a civilian.
On a foreign policy trip in Asia, U.S. President Barack Obama called Egyptian President Mohamed Morsi to discuss how to de-escalate the situation in Gaza. The White House said Obama stressed the need for Hamas ending rocket fire into Israel.
Obama then called Israeli Prime Minister Binyamin Netanyahu and received an update on the situation in Gaza and Israel. In both calls, the White House said, Obama expressed regret for the loss of Israeli and Palestinian civilian lives, and agreed to stay in touch with both leaders.
Israeli planes have been striking at night in an attempt to avoid civilian casualties, CBS News reported, but civilian deaths were mounting in one of the most densely populated areas in the world.
Though Morsi said he's hopeful a cease-fire agreement can be reached quickly, a source close to the Hamas delegation in Cairo told CBS the talks had hit an impasse.
One of the reasons for the impasse is a Hamas demand that Israel end its five-year blockade of Gaza, CBS said. Israel fears lifting the blockade would lead to a flood of weapons into Gaza.
Earlier, Israel agreed to delay sending ground forces into Gaza to allow time for cease-fire talks, an Israeli official told The Jerusalem Post.
"Israel prefers a diplomatic solution," the official said.
The conflict had its most violent day Sunday.
Israeli missiles were reported to have killed at least 30 Palestinians, including 10 members in three generations of a single family when a Gaza City home was flattened by an bomb.
Israel massed armor on the Gaza border and called up 40,000 reservists, in addition to its regular standing army of about 175,000. The military said it could add 35,000 more troops.
In Cairo Monday, Hamas leader Khaled Mashaal told a news conference Hamas knows Israel is "capable" of conducting an invasion, which he said would not "be a picnic, but a political disaster" for Netanyahu.
Turkish Prime Minister Recep Tayyip Erdogan called Israel a "terrorist state" Monday. Erdogan made the comment shortly after returning from Cairo where he held emergency talks on Gaza with Morsi, The Wall Street Journal reported.
"Those who speak of Muslims and terror side-by-side are turning a blind eye when Muslims are massacred en masse," Erdogan told the Eurasian Islamic Council. "Those who turn a blind eye to discrimination toward Muslims in their own countries are also closing their eyes to the savage massacre of innocent children in Gaza. ... Therefore, I say Israel is a terrorist state."