Indian Muslim girl takes part in  candle march to condemn terrorist attacks and in memory of those killed, in Mumbai, 30 Nov 2008

 India has demanded strong action from Pakistan against those responsible for the deadly Mumbai attacks, which have fueled fears of a sharp deterioration in relations between the nuclear armed neighbors.

India's Foreign Ministry summoned Pakistan's envoy in New Delhi (Shahid Malik) Monday to lodge a formal protest and to inform him that the attacks were carried out by "elements from Pakistan."

India's junior foreign minister (Anand Sharma) called the Mumbai massacre a setback to the process of normalizing relations between the two countries. 

Also Monday, U.S. Secretary of State Condoleezza Rice said Washington expects clear and transparent cooperation from Islamabad on the Mumbai carnage. Speaking in London before going to India Wednesday, Rice said the United States will work with both India and Pakistan to help bring those responsible to justice.

British Foreign Secretary David Miliband said London will do everything possible to calm tension between India and Pakistan, adding that the stakes are very high.

Pakistan has repeatedly denied any involvement by its state agencies and has vowed to cooperate fully in the terror probe.

U.S. President George Bush has pledged full support for the investigation into the Mumbai siege that killed about 175 people, including six Americans.

The United States and Britain have dispatched teams of investigators to Mumbai to assist Indian authorities.

Pakistani Prime Minister Yousuf Raza Gilani called for Pakistan's political leaders to assemble on Tuesday to develop a so-called "national consensus policy" on India.