Survivors of a massive earthquake that struck Haiti on Tuesday face “untold suffering”, warns Christian Aid, as aid agencies scramble to bring relief and join in the rescue effort.

Thousands are feared dead following the 7.0 magnitude quake which struck 15km southwest of capital Port-au-Prince just before 5pm local time. Buildings across the capital were toppled, including the presidential palace and the headquarters of the UN mission in Haiti. It is believed that there are no survivors inside the collapsed UN building.

Dame Anne Owers, chair of Christian Aid, said she was deeply concerned about the impact of the earthquake on already severely impoverished communities in the Caribbean nation.

“It is one of the poorest places on earth. This latest disaster is going to cause untold suffering and hardship, particularly in communities with very little to fall back on,” she said.

She said there was an urgent need for emergency supplies, including food, shelter and medicine, while in the longer-term, rebuilding would require “massive international assistance”.

“I appeal to people and to governments to give what they can,” she said.

The earthquake is the strongest to hit Haiti in 200 years and could be felt as far away as Cuba.

Three Christian Aid staff members had to be rescued after their office collapsed, although none were seriously injured. Many churches had also been completely destroyed.

Christian Aid’s Caribbean Regional Manager Judith Turbyne said the national response was unlikely to be sufficient because of Haiti’s weak state and the lack of resources at its disposal. She said there was a huge need for a “concerted effort” from the large aid community in the country.

World Vision also anticipates a difficult response to the earthquake. World Vision aid worker Crystal Penner said it would be a challenge to bring relief items prepositioned around the country to the people in need of them.

Edward Brown, World Vision’s relief director in the US, said: "We would be very concerned about a quake of this magnitude anywhere in the world, but it is especially devastating in Haiti, where people are acutely vulnerable because of poor infrastructure and extreme poverty."

World Vision’s disaster response experts were due to arrive in the capital today to begin assessing the scale of the damage and the aid agency’s response. It is readying basic items like first aid kits, soap, blankets, clothes and bottled water to be distributed in the coming days to survivors.

Tearfund announced it was also sending disaster specialists to help partners assess immediate needs and dispatching emergency funds. Chief Executive Matthew Frost said communications had been severely disrupted, making logistics extremely difficult for emergency and relief agencies.

He said: “Please support our partners in prayer as they themselves face the immense scale of disaster, the trauma, the destruction and loss of life that this earthquake has brought.”

The Methodist Church has already donated £20,000 to the rescue effort and has launched an emergency appeal for more funds to reach survivors.

The Rev Marcus Torchon, a Haitian Methodist minister serving in the Liverpool District on an exchange programme, said he was still waiting for news from family members who are so far missing.

“I managed to speak to my nephew after the quake happened, but since that phone call there were more than 10 after-shocks. Now the line is dead because the major phone networks are down,” he said.

“It is really destabilising emotionally. Practically, I would like to be of service to them. I feel that at some point I may have to go there when the airport is open. At the end of the day, we have nothing but our faith in God.”

The Methodist Church in Haiti has 12,000 members, making it the largest membership district of the Methodist Church in the Caribbean and the Americas.

The Rev Tom Quenet, partnership coordinator for the Americas and Caribbean, said he had managed to make contact with the President of the Methodist Church in the Caribbean and the Americas this morning.

“Following the damage caused by four successive hurricanes that hit the island in 2008, I fear that the people of Haiti will wake up to scenes of devastation, fear and loss of life.”