The United Nations on Friday rejected Israeli claims that Lebanese Hezbollah militants were establishing observation posts along the border under the cover of an environmental NGO.

The Israeli military on Thursday published pictures of a building near the Israeli-Lebanese border supposedly controlled by an organisation called Green Without Borders.

The UN peacekeeping mission UNIFIL reported that Green Without Borders members have planted trees in the area, but it "has not observed any unauthorized armed persons at the locations or found any basis to report a violation of resolution 1701," said UN spokeswoman Eri Kaneko. 

Israel's ambassador to the UN, Danny Danon, had sent a letter of protest to the Security Council with images of the alleged observation posts and maps locating them.

Dannon described the activities as a "dangerous provocation" and said Hezbollah was carrying out reconnaissance activities near the Blue Line border demarcation while posing as a civilian organisation.

Israel fought a month-long war against the Lebanese Shite movement in 2006, killing more than 1,200 Lebanese, mostly civilians, and more than 160 Israelis, mostly soldiers.

Resolution 1701 was adopted to end the war, calling for full respect of the Blue Line.