The Guards' acting commander told state TV that the tests, aimed at mock enemy bases in a war game exercise, were a response to Israel's and Washington's refusal to rule out military strikes to stop Iran's nuclear program.
"It is a response to the political impoliteness of those who talk about all options being on the table," Gen. Hossein Salami said.
The official IRNA news agency said the surface-to-surface missiles successfully hit their targets, while semi-official Fars said the salvos included the so-called Shahab-3 missile. It quoted a leading officer as saying the missiles travelled distances of up to 1,300 kilometers, or 800 miles.
Iran has tested a variety of missiles in previous war games, including a Shahab-3 variant with a range of 2,000 kilometers that can reach Israel and southern Europe. The launched missiles are also capable of hitting U.S. bases in the region.
Iranian state TV showed footage of several missiles being launched.
"So far, we have launched missiles from 300 to 1,300 kilometers in the maneuver," said Gen. Amir Ali Hajizadeh, who heads the Guards' aerospace division. He hinted that some missiles had an even longer range.
Israel is about 1,000 kilometers away from Iran's western borders, while the U.S. Navy's Fifth Fleet is based in Bahrain, some 200 kilometers from Iranian shores in the Persian Gulf.
The Iranian commander quoted by Fars said Iran used both unmanned and manned bombers in the war games, and was firing a variety of other missiles. Tehran says the drills aim to assess the accuracy and effectiveness of its warheads and weapons systems.
On Sunday, a European Union oil embargo meant to pressure Iran over its nuclear program came into effect.
The West suspects the Islamic Republic wants to build nuclear weapons, and Israel has hinted at an attack if diplomatic efforts and sanctions fail to eliminate what it sees as a direct threat.
Iran insists its nuclear program is for peaceful purposes, such as power generation and cancer treatment.