Five US warplanes entered Iran's airspace last Thursday night from the country's southwestern border,an Iranian newspaper reported Tuesday.

The Persian daily Seday-e Edalat said the five US jet warplanes entered Iran from the southwestern Shalamcheh border and flew over the border city of Khorramshahr for a while.

The planes flew at a height of 10 kilometers overhead the city before heading to the Arvand River, the Iranian part of the Shattal-Arab waterway, the paper added.

While the objective of the fight violation was not known yet,some military specialists believed such moves were aimed at assessing the sensitivity of Iran's anti-aircraft defense system,the paper said.

Military and air force officials didn't make comments on the incident, according to the report.

In June, three British boats and eight marines aboard were detained for several days by Iranian naval guards for their alleged intrusion into Iran's territorial waters in Arvand river.

Source: Xinhua