LONDON, Dec 21 (AlertNet) - Aid organisations found it harder to operate in 2008 and help some of the world's most vulnerable people than in previous years because of increased security risks and more hazardous environments, a leading medical NGO said on Sunday.

In its annual list of "top 10" humanitarian crises, Medecins Sans Frontieres (MSF) said many of the countries on this year's list - including Somalia, Pakistan, Sudan and Iraq - illustrated the growing difficulties aid groups faced.

"In some of these places, it is extremely difficult for aid groups to access populations requiring help," MSF International Council President Christophe Fournier said.

"Where we are able to provide assistance, we have a special responsibility to bear witness and speak out about intolerable suffering and draw attention to basic humanitarian needs - needs that are often largely ignored."

Intensified violence in Somalia, including direct attacks and threats on aid workers, meant MSF had to curtail some of its operations in 2008 and withdraw its international staff, the report said.

In northwest Pakistan, hundreds of thousands of people fled air attacks and bombings from a counter-insurgency campaign earlier in the year. After aid workers in the country were threatened, attacked and kidnapped, MSF restricted the number of international staff working on its projects.

"The reality on the ground is that the humanitarian community is unable to do nearly enough for populations in grave need of medical assistance," Fournier said.

"With the release of this list, we hope to focus much needed attention on the millions of people who are trapped in conflict and war, affected by medical crises, whose immediate and essential health needs are neglected, and whose plight often goes unnoticed."

MSF said governments were also to blame for a worsening situation for aid workers in the field, which was leading to hundreds of thousands of people dying needlessly.

In Myanmar and Zimbabwe, where governments failed to make health care a priority or viewed NGO involvement with suspicion, humanitarian organisations were either limited in the type of assistance they could provide or were left to deal with health crises alone.

Governments were also ignoring the crisis of childhood malnutrition. In Niger this year, the government forced MSF to close its child nutrition program in the region of Maradi, where tens of thousands of children were suffering from acute malnutrition.

The complete MSF list (with key facts from MSF and AlertNet briefings):

1. Somalia's humanitarian catastrophe worsens

More than 3.2 million need humanitarian aid

More than 1.1 million displaced

Infrastructure in tatters and little law and order Somalia anarchy: AlertNet briefing

2. Myanmar: despite attention brought on by cyclone, medical needs go ignored

Over 2 million affected

Damage estimated at $4 billion

U.N. appeal underfunded Myanmar cyclone: AlertNet briefing

3. Civilians trapped as war rages in eastern Congo

5.4 million dead since 1998 from war-related violence, hunger and disease

Congo is the size of western Europe

At least 40,000 women and girls have been raped Congo conflict: AlertNet briefing

4. Health crisis sweeps Zimbabwe as violence and economic collapse spread

Female life expectancy 43 years

Agriculture devastated

World's highest inflation Zimbabwe crisis: AlertNet briefing

5. Millions of malnourished children left untreated despite advances in lifesaving therapies

Enough food is produced globally to feed the planet but even so roughly 923 million people go to bed hungry every night

Hunger is a leading cause of death, killing an estimated 9 million people every year - more than AIDS, tuberculosis and malaria combined

A child dies of hunger every five seconds (UN World Food Programme) Food and hunger: AlertNet topic

6. Civilians denied assistance in Ethiopia's Somali Region

Ethiopia cracks down on rebels after deadly attack on Chinese oil installation

Troops accused of burning homes, displacing thousands

Ethiopia accuses rival Eritrea of backing rebels it calls terrorists Ethiopia unrest: AlertNet briefing

7. Civilians killed and forced to flee as fighting intensifies in northwestern Pakistan

Regions of Pakistan that border Afghanistan are plagued by violence between militants and government security forces

Some militant violence has spilled into other parts of the country

The recent political crisis has seen an increase in suicide attacks on troops and other targets Pakistan violence: AlertNet briefing

8. No end in sight to conflicts in Sudan

At least 300,000 have died and 2.9 million been displaced by fighting since 2003 in Darfur in the west

Tensions in eastern Sudan where insurgents have threatened to challenge the government for a share of the country's power and natural resources

Life expectancy at birth is 57.4 years Sudan conflicts: AlertNet briefing

9. Iraqi civilians in urgent need of assistance

Millions displaced by violence

Basic services devastated by sanctions and war

Few international aid workers left Iraq turmoil: AlertNet briefing

10. HIV/TB co-infection: a health battle on two fronts

Most HIV-positive people don't know they're infected

Women make up nearly 60 percent of new infections in sub-Saharan Africa

Anti-retroviral drugs reach only 31 percent of those who need them AIDS pandemic: AlertNet briefing