Prime Minister Manmohan Singh [Images] arrived in Delhi [Images] on Sunday night winding up his three-day visit to Colombo where he attended the 15th South Asian Association for Regional Cooperation Summit and held bilateral talks with leaders of Pakistan and other countries.

Dr Singh was given a warm send-off, with Sri Lankan Prime Minister Ratnasiri Wickremanayake seeing him off at the airport.

Dr Singh met his Pakistani counterpart Yousuf Raza Gilani on Saturday during which he conveyed his concern about the attack on Indian Embassy in Kabul, ceasefire violations by Pakistan and rising infiltration in Jammu and Kashmir [Images].

Responding to Dr Singh's concerns, Gilani said he would conduct an independent investigation into the Kabul attack.

In the meeting, Dr Singh made it clear to Gilani that recent incidents had put the relationship and future of the dialogue in a "difficult" situation and Islamabad [Images] must act to address New Delhi's concerns.

Addressing the eight-nation Summit on Saturday, Dr Singh warned that terrorism has emerged as the "single biggest threat" to stability. 

Dr Singh also asked SAARC countries to jointly battle the "ideologies of hatred" and those seeking to destroy their social fabric.

"Terrorism [Images] continues to rear its ugly head in our region. It remains the single biggest threat to our stability,"  Dr Singh said.

Dr Singh met Nepal's caretaker Prime Minister Girija Prasad Koirala on Sunday and assured him of India's continued support to the Himalayan state's democratic transition.