KABUL, Feb. 21 (Xinhua) -- Four Taliban insurgents were killed since Afghan army launched an operation in western province of Herat, the Defense Ministry said on Wednesday.

"Four terrorists were killed and one arrested after Afghan National Army (ANA) launched a cordon operation in Gulran district Tuesday," the ministry tweeted.

Four motorcycles, rounds of ammunition and weapons were also destroyed after the raid in the district bordering Iran and Turkmenistan.

The Afghan government forces have lately beefed up security ahead of the inauguration of a major gas project in Herat, 640 km west of Kabul.

Afghan leaders and foreign guests from regional countries will participate, within coming days, in the groundbreaking ceremony of the mega project which will mark start of the construction of Turkmenistan-Afghanistan-Pakistan-India (TAPI) Gas Pipeline Project in the Afghan terrain.