The missile manoeuvres coincided with increased tension in Iran's nuclear dispute with the West, after last week's disclosure by Tehran that it was building a second uranium enrichment plant.
The tests also came just days before talks with the five permanent members of the UN Security Council and Germany on the Islamic Republic's nuclear programme.
Sacred Defence week
On Sunday, Iran tested two short-range missiles as part of its Sacred Defence week, that cemmemorates the start of the Iran-Iraq war in 1980.
Al Jazeera's Alireza Ronaghi, reporting from Tehran, said: "The most important thing is that this Shahab 3 missile can reach targets as far as 2,000km. It's the longest-range missile in the Iranian arsenal."
"There are two solutions about Iran: one would be sanctions and the other would be military action. So [with regard to] sanctions, Iran is trying to prove that sanctions have not worked on the uranium enrichment programme," our correspondent said.
"And as far as the military option is concerned, Iran is showing off missiles trying to say that a military option is not going to be viable; it's not going to be a hit-and-run.
"Iran will retaliate and it will not just limit itself to the countries that have led those attacks; it will be a wide range retaliation. This is the message that Iran is sending."
The missile tests are likely to exacerbate tensions between Iran and the West over Tehran's nuclear programme.
Iran stages regular military manoeuvres in the strategic Gulf waters, showcasing its long- and medium-range missiles as well as other weaponry.
Theodore Karasik, a defence analyst based in Dubai, told Al Jazeera: "The range [of the missiles], of course, is critical and if they decide to fire the missiles they would be able to hit various targets based on their selected need.
"The question becomes the accuracy of these missiles, and the earlier series of these Shahabs were notoriously inaccurate. In military parlance, that's called circular error probability. This raises the issue of the sophistication of Shahab 3."
Iran and the five permanent members of the UN Security Council, along with Germany, are scheduled to meet in Geneva to discuss Tehran's disputed atomic programme on October 1.
New enrichment site
The International Atomic Energy Agency (IAEA) said last week Iran was building a second uranium enrichment plant.
The suspected nuclear site in the arid mountains near the city of Qom is believed to be inside a heavily guarded, underground facility belonging to the Revolutionary Guards, according to a document sent by the White House to US legislators.
After the strong condemnation from the US and its allies, Iran said on Saturday it would allow UN nuclear inspectors to examine the site.
Hillary Clinton, the US secretary of state, welcomed the announcement by Ali Akbar Salehi, the head of Iran's atomic energy organisation.
"It is always welcome when Iran makes a decision to comply with the international rules and regulations, and particularly with respect to the IAEA," she said.
But Clinton also said the US does not believe Iran can convince world powers at the forthcoming Geneva meeting that its nuclear programme is for peaceful purposes, putting Tehran on track for tougher sanctions.
|The suspected nuclear site is in the arid mountains near the city of Qom [AFP]
The Iranians must "present convincing evidence as to the purpose of their nuclear programme. We don't believe that they can present convincing evidence, that it's only for peaceful purposes, but we are going to put them to the test," Clinton told the CBS programme Face the Nation.
Western powers, along with Israel, suspect Iran wants to use its nuclear technology to make weapons.
Israel has also trumpeted the latest discoveries as proof of its assertion that Iran is seeking nuclear weapons.
But Tehran insists its nuclear programme is aimed at generating electricity for civilian purposes.