Pakistani President Asif Ali Zardari has ended his visit to the UK with a speech to supporters in Birmingham.
A prayer was also offered for Mr Zardari's wife, the former Pakistan prime minister Benazir Bhutto, who was assassinated in 2007.
The BBC's Rajini Vaidyanathan, at the rally, said there was heckling; a shoe was reportedly thrown at Mr Zardari.
Meanwhile the president's son, Bilawal Bhutto Zardari, opened a donation point in London for Pakistan's flood victims.
Mr Zardari gave his speech in Urdu at a rally at the Birmingham ICC conference centre.
An elderly man was taken away by police after he shouted at the president, and other people walked out in protest.
One man said he walked out because he believed the president should not be in the UK. The president has been criticised for not returning to Pakistan after the country was hit by devastating floods.
West Midlands Police said it was investigating the shoe-throwing incident.
A spokesman said: "This case will be discussed with the high commission to see how they wish to proceed."
'Drumming up support'
Mr Zardari's son cancelled an appearance at the Birmingham event, saying he would open the donation point at Pakistan's High Commission in the capital.
There had been claims that that he would make his first major political speech at the rally, following his recent graduation from Oxford University.
But in a short statement at the donation point, he said it had "never" been his intention to join his father in Birmingham and insisted that suggestions he was using his father's visit to launch his political career were "all lies".
"This is not the time to play politics. We need to do whatever is necessary to help our brothers and sisters in Pakistan," he added.
The 21-year-old is co-chairman of the Pakistan Peoples Party, along with his father.
International Development Secretary Andrew Mitchell defended President Zardari's visit which he said had served to highlight the disaster and help raise international relief funds.
"He is drumming up support internationally for the huge relief effort that is going to be required now in Pakistan and is going to be returning very soon. I think he is right to continue that visit."
On Sunday the Disasters Emergency Committee revealed that the British public has donated £4m for flood victims in less than two days.
The government had already pledged £10m of aid to the country.
During an interview with BBC Newsnight Mr Zardari also restated his commitment to fighting terrorism, following talks with UK Prime Minister David Cameron.
He said: "I don't think anybody doubts our intentions on this war."
But he refused to be drawn on whether he had tackled Mr Cameron over recent comments about Pakistan promoting terror.
He said the two men had focused on the "positive" in their discussions.
"We engaged in conversation like two adults," said Mr Zardari.
The leaders issued a joint communique following their talks at Mr Cameron's country retreat Chequers, stressing their commitment to work more closely in future in the battle against terrorism, and in other areas such as education and trade.
On Friday Mr Cameron hailed the "unbreakable" friendship between Britain and Pakistan.
He said their talks had focused on making sure "we deal with all the issues where we want to make progress, whether that is in trade, whether it's in education, and also in the absolutely vital area of combating terrorism".
Mr Zardari said that Pakistan and the UK had a "friendship that will never break, no matter what happens".
However, he told the Times Mr Cameron's comments had hurt him personally.
"Everybody is sensitive, as we have lost so many people, including my late wife (Benazir Bhutto), so to have your credentials questioned does hurt sometimes. No matter how brave you are, it hurts," he said.
Mr Zardari has rejected criticism that he should have stayed at home to lead relief work, as numbers hit by the floods reached some 12 million.
Labour MP Khalid Mahmood accused Mr Zardari of not having "any empathy or sympathy" with what his people were going through as the country was left devastated by its worst monsoon floods in 80 years.
Asked in the Newsnight interview about such criticism, Mr Zardari said he was being kept up to date with the situation, but it was the responsibility of Pakistan's prime minister, who was the country's "chief executive".