WAFIDEEN CHECKPOINT (Syria) • Syrian and Russian forces kept up military pressure on rebel-held Eastern Ghouta yesterday as their controversial unilateral truce failed to yield a humanitarian breakthrough.

More than 40 trucks loaded with aid were unable to reach the 400,000 people living in the battered enclave, prompting fresh calls for a United Nations ceasefire to be implemented.

A five-hour daily "pause" announced by Moscow on Monday has led to a reduction in the bombardment that killed hundreds in only a few days and sparked global outrage last month. But the humanitarian corridor offered by Russia for civilians to flee appeared empty for a third day running, with distrust running high on both sides.

The only civilians to leave Eastern Ghouta this week were a Pakistani man in his 70s, who moved to Syria 44 years ago, and his wife, according to the local Red Crescent.

Syrian aircraft carried out strikes yesterday before the 9am start of the "truce", killing seven civilians, according to the Syrian Observatory for Human Rights, a British-based war monitor.

The Russian military said yesterday that Syrian rebels killed four civilians during a protest, news agencies reported, citing Major-General Vladimir Zolotukhin, who was speaking in Damascus. He said the killings showed that the rebel threats against people who wanted to leave were real.

Air strikes have eased compared with last week when the joint Syrian and Russian aerial campaign against Eastern Ghouta killed up to 100 civilians a day.

But the death toll for the assault launched on Feb 18 continued to mount, even after Russia's "humanitarian pause" kicked in, as rescuers found bodies they had been unable to access.

According to the United Nations, three quarters of all private housing in Eastern Ghouta has been damaged and hundreds of civilian need life-saving medical evacuations.

The Russian daily "pause" falls far short of a 30-day ceasefire voted for by the United Nations Security Council last Saturday, which has yet to be implemented.

UN officials yesterday repeated their criticism that the five-hour window was too short and needed to be upgraded to allow aid deliveries and medical evacuations.

UN Syria envoy Staffan de Mistura said the UN would not give up seeking a full 30-day ceasefire.

His humanitarian adviser Jan Egeland said diplomats from 23 states attending a humanitarian meeting yesterday had been given a blunt message: "You are failing to help us help civilians in Syria."

Russia and its allies in Syrian President Bashar al-Assad's regime have blamed the humanitarian deadlock on armed groups controlling Eastern Ghouta.

Syrian state media and military sources accuse the groups of deliberately shelling the designated safe passages to prevent civilians from leaving and keep them as human shields.

AGENCE FRANCE-PRESSE, REUTERS