Vice Admiral Mark I. Fox, Commander of the U.S. 5th Fleet, warned on Sunday against “suicide ships” Iran may plant along the Straits of Hormuz in order to use against U.S. forces that try to break the blockade in the area.

Israel’s Channel 2 News quoted Fox as having told reporters that Iran has “increased the number of submarines at their disposal and also acquired a number of ships that can be used for suicide missions when necessary.”

Fox also warned of Iran’s capabilities of firing long-range missiles and said, “We are following with interest the development of missiles and rockets that can hit ships in our fleet. The Iranians can make things difficult for us during an operation and we are taking their threats seriously.”

Last week, Iranian officials said that the Islamic Republic is conducting yet more military exercises in the Straits of Hormuz and that the exercises were in response to a European boycott of Iranian oil.”

Iranian television said that the exercises would continue for a month. The report added that Iran had no plans to interfere with sea traffic through the Straits.

The Straits of Hormuz are considered an important strategic asset; 20% of the world's production of oil passes through it on oil tankers bound for the West, and Iran has threatened to close the Straits if its nuclear facilities are attacked.

In addition to the exercises, Iranian officials said last week that they had developed a new short-range missile designed to shoot down missiles fired at Iran from warships. The Zafar is a short-range anti-vessel radar-guided cruise missile, which can target small and medium-sized targets with high precision, officials said. The missile “loses altitude after being launched, and then cruises at low altitude in order to be hidden from sight of the enemy, and in the final stage identifies the target at a low altitude and destroys the target,” the official added.

On Saturday, Iranian President Mahmoud Ahmadinejad said that Tehran will soon unveil “big new” nuclear achievements.

Speaking at a rally in Tehran marking the 33rd anniversary of the Islamic Revolution that toppled the pro-Western monarchy and brought Islamic clerics to power, Ahmadinejad said, “Within the next few days the world will witness the inauguration of several big new achievements in the nuclear field.”

He did not specify what those big new achievements are.