KABUL, April 25 (Xinhua) -- The Taliban militants on Wednesday announced the start of their yearly rebel offensive in Afghanistan, the outfit said in a statement.

Zabiullah Mujahid, a purported Taliban spokesman, said in the statement that their offensive codenamed "al-Khandaq jihadi" operation started early Wednesday.

"Both our land and air space are under the control of foreign occupying forces and our religious sanctities as well as helpless people are indiscriminately being targeted," the Taliban statement said.

"The existence of multiple American bases set up under the Strategic Agreement between the American invaders and the puppet regime in Kabul are reasons through which America sabotages all chances of peace and plays crucial and decisive role in intensifying and prolonging the ongoing war in Afghanistan...," it said.

The Taliban militants, who ruled the country before being ousted in late 2001, renewed armed insurgency, killing government troops as well as civilians.

They urged civilians to stay away from official gatherings, military convoys and centers regarded as the legitimate targets by militants besides warning people not to support the government.

The NATO and U.S. forces completed their combat mission in Afghanistan by the end of 2014 after 13 years of military presence in the country. But around 16,000 foreign troops remain in the country to train and assist the Afghan forces.

Following the announcement, the Taliban claimed multiple attacks across the country.