* President of aid agency says situation worsening
* Red Cross unable to reach many civilians
* Says it urged Assad to allow 25 prison visits by year-end
By Stephanie Nebehay
GENEVA, Nov 8 (Reuters) - The International Committee of the Red Cross said on Thursday it could not keep pace with the growing needs of civilians caught up in Syria's worsening civil war.
Peter Maurer, ICRC president, said its staff had tried to exploit "cracks" in shifting front lines to deliver supplies to hotspots, as it had managed to do in Homs at the weekend.
But many civilians remained out of reach. "We have a lot of blank spots, we know that no aid has been there and I can't tell you what the situation is," he said.
Maurer likened it to "flying a plane without instruments" because of the difficulty of assessing the number of wounded or civilians lacking food, water and sanitation.
"We are in a situation where the humanitarian situation due to the conflict is getting worse. And despite the fact that the scope of the operation is increasing, we can't cope with the worsening of the situation," he told a news briefing.
Maurer, who held talks in Damascus with Syrian President Bashar al-Assad in early September, said the ICRC had been able to import food and medical supplies more smoothly in the last two months. It has brought in 14 big lorries to transport supplies and secured warehouses with direct access to its goods.
However, its team led by Marianne Gasser faced a complex and dangerous situation in trying to deliver assistance across Syria, where at least 1.2 million are internally displaced.
"It's an issue sometimes of bureaucratic restrictions, sometimes of military strategic restrictions and sometimes just of security decisions of our delegation not to go into a certain context," he said.
After days of negotiations, on Saturday the ICRC reached two neighbourhoods in the Old City of Homs, delivering medical items to treat up to 100 wounded and medicines against chronic diseases. Food and hygiene items for 1,200 were also delivered.
"It is a complicated negotiation because you are negotiating at the front line. And the front line is again relatively clearly structured on the one side, it's less clearly structured on the other, and it's pretty dangerous to go into such situations," Maurer said, referring to divisions in rebel ranks.
ICRC staff, mainly confined to Damascus, have access to Idlib in the north but have not been to Aleppo in "quite some time", he said.
A Syrian opposition watchdog estimates that 38,000 people have been killed in the 19-month-old revolt against Assad.
A medical aid group, the Syrian Medical Relief Organizations (UOSSM), said on Wednesday Syrian troops were seizing foreign aid and reselling it or channelling it towards government loyalists, putting millions of lives at risk.
The ICRC has a "relationship of confidence" with the Syrian Arab Red Crescent (SARC), but the SARC's Damascus branch may be closer to the government than other branches, Maurer said.
"I cannot guarantee that you don't find examples where an action of the SARC is not neutral or independent but rather guided by political intentions. I cannot exclude that," he said.
Maurer said he had urged Assad to allow access to 25 prisons across Syria by year-end. It has only visited prisons in Damascus and Aleppo so far and its confidential findings are shared only with authorities.
"We are still in difficult negotiations trying to expand the scope of prison visits in Syria," he said.
"We haven't visited (detained) soldiers but we engage on issues of detention as well as conduct of hostilities with elements of the Syrian opposition forces."