Two Iranian navy ships have docked at Sudan's main port of the Red Sea, underlining Tehran's military links to Sudan in the wake of last week's airstrike, with Israel suspected to have carried out the attack, on an arms factory near Khartoum.

The two events illustrate how East Africa and the Red Sea that runs between two strategic waterways -- the Suez Canal in the north and the Bab al-Mandeb Strait in the south -- have become an occasional battleground for Israel and Iran.

Israel says Iran's Revolutionary Guards Corps' covert operations arm, the al-Quds Force, uses the Red Sea to smuggle weapons to Palestinian militants in the Hamas-ruled Gaza Strip as well the Iranian-backed Hezbollah in Lebanon via Sudan and Egypt.

The Guards also allegedly send arms to Shiite Houthi rebels in northern Yemen, most likely through Eritrea, Sudan's southern neighbor on the western shore of the Red Sea. These arms are reportedly shipped from the Iranian port of Bandar Abbas, a major base in the southern Persian Gulf for the Guards' naval arm, since at least 2009.

At the same time, Iran has been expanding its naval forces, the regular navy as well as the Guards' naval wing, both of which until recently had confined their operations to the gulf.

The Guards' focus is now on the Strait of Hormuz, the only gateway to the gulf and a strategic oil artery, and the Gulf of Oman at the southern end of the strait.

The regular navy, which includes three Russian-built Kilo class attack submarines, several destroyers and Chinese-built missile craft, was ordered to develop a blue-water force and extend Iranian naval influence further afield.

"A new evolving strategy has now caused Iran to send military vessels to other waters, including the Gulf of Oman, the Caspian Sea, the Red Sea and even the Mediterranean Sea" for the first time since the Islamic revolution in 1979, observed Israeli analyst Shaul Shay of Tel Aviv's Begin-Sadat Center for Strategic Studies.

Tehran's "aggressive new strategy ... threatens to block key straits in the Red Sea and the Persian Gulf that would cripple Western shipping routes," he said in a July report on Iran's strategic objectives.

The naval forces are important for maintaining and expanding Iranian arms smuggling routes, and Sudan, an Iranian ally since the 1980s, is the key element there.

Iranian vessels regularly dock at the Eritrean ports of Massawa and Assab.

In 2008, Eritrean opposition forces claimed the government in Asmara had allowed Iran to establish a naval base at Assab, just north of the Bab al-Mandeb Strait, the narrow waterway linking the Red Sea and the Indian Ocean.

The Israeli navy has intercepted ships carrying Iranian arms in the Red Sea. In 2010, the air force reportedly destroyed three convoys in Sudan carrying weapons bound for Gaza.

That increases the likelihood the Oct. 24 airstrike that destroyed part of the Yarmouk arms plant involved the Israeli air force.

Khartoum has accused Israel of the raid, in which two people were killed. Israel has made no official comment but senior figures have dropped strong hints the air force was responsible.

The U.S. global intelligence consultancy Stratfor says the Yarmouk factory was believed to manufacture ammunition and rocket artillery destined for Gaza and al-Houthi rebels in Yemen.

"The factory is thought to have ties to the Revolutionary Guards' Al-Quds Force and is said to be staffed by Iranians," Stratfor noted.

In June, two members of the Al-Quds Force were arrested in Kenya with RDX explosives, possibly for an attack on Israeli interests in the East African state.

Sudanese officials say four Israeli aircraft took part in the Oct. 24 night attack.

But the Sunday Times of London, citing Israel security sources, said the raid consisted of four F-15I Raam fighter-bombers, each armed with two 1-ton bombs, and four F-15 escort fighters.

The latter group wouldn't likely have been seen from the ground.

The eight jets were refueled in flight during the 2,500-mile round trip by a Boeing 707 tanker, the newspaper said, while a Gulfstream G-500 electronic warfare jet blinded Sudan's rudimentary air defenses.

Some analysts saw the strike as a rehearsal for long-range strikes on Iran. There's no hard evidence of that but the air package involved was a small-scale version of what would be required.