KABUL, July 1 (Xinhua) -- Up to 158 Afghan civilians were killed and 355 injured in clashes and terrorist attacks in June, a monitor group reported Sunday.

"Some 158 civilians were killed and 355 others injured in 22 of the 34 provinces of Afghanistan last month," independent Civilian Protection Advocacy Group (CPAG) said in a press release.

Most of the casualties occurred in eastern Nangarhar province, where 46 civilians were killed and 130 others injured, followed by eastern Kabul and western Herat province, the release read.

"In addition, civilians have been targeted and displaced as a result of security forces and the Taliban clashes elsewhere," it added.

The monitor group added that the U.S. and NATO-led coalition forces also inflicted casualties on civilians during last month.

Six civilians were killed and one injured in a U.S. forces' airstrike in Waygal district of eastern Nuristan province in late June, the statement said.

The group urged the armed groups to respect the rules of war and pay attention to the protection of civilians.

In May, 183 civilians lost their lives and more than 337 injured as a result of terrorist attacks and clashes across the country, according to figures of CPAG.