The mother of a five-year-old British boy kidnapped in Pakistan yesterday begged her son's captors to release him, saying: "What has he done to anyone? He's just a sweet little boy."

Sahil Saeed was kidnapped by an armed gang while on holiday with his father in Pakistan. He was taken from his grandmother's home, in the Punjab region, on the day he was due to return to his home in Oldham.

His captors are demanding a £100,000 ransom which Sahil's family say they have "no chance" of paying.

Yesterday, in an emotional television appearance from her Greater Manchester home, his mother Akila Naqqash said: "We can't do anything from here – all we can do is pray that they will bring my son back. He is a sweet boy, so bubbly and gets along with everybody.

"We have got no idea why we were targeted – we don't have any money. There is no way we could raise that money; there is nothing we can do."

When asked what she would say to the kidnappers, she added: "What has he done? He's just a five-year-old boy. Bring him back please."

Sahil and his father had been staying with the boy's grandmother in Jhelum during a two-week trip when the gang burst into the house at about 11pm local time.

The boy's father Raja Naqqash Saeed said that the four men, who had guns and hand grenades, attacked him and other relatives at the house, beating, slapping and kicking them during a six-hour ordeal.

He told Sky News: "They took me into a separate room and they tortured me. They said 'We will take your son and you will have to pay £100,000'."

They eventually fled with the boy and household items, and, it is believed, 150,000 rupees (£1,160) in cash and some jewellery. Initially the gang are reported to have told Mr Saeed that they would telephone with instructions, but that call is not thought to have been made.

It was not immediately clear what the motive behind the kidnap could have been. There is not any obvious political motive although there have been incidents of businessmen being kidnapped for ransom money in recent months.

And while many people visiting the area choose to travel with private security guards, the region is not particularly vulnerable to the Taliban.

Last night it was reported that police in Pakistan had arrested a man whom they described as the "prime suspect" – a taxi driver who came to pick the pair up from the house and drive them to the airport. The man was said to be the same driver who had collected Sahil and his father when they arrived at Rawalpindi airport last month.

But both the police and officials at the Punjab government denied that any arrests had been made in the case.

The government official added that three teams had been set up to search for the child and that early investigations had traced phone numbers that are potentially linked to suspects, one of which originated in Denmark. Sources also said that the kidnapping was "highly professional".

Mr Saeed said the kidnappers had originally put a noon deadline on the ransom for his safe return. But it is thought that deadline passed without any word from the boy's captors.

Ms Naqqash, who also has two daughters, Anisha, four, and Hafsah, 21 months, said she had heard nothing from the kidnappers. She added: "My husband would swap places if he could; he said to them: 'Take me, I'll be your hostage.' We just want him back home. I found out at 7.45am when my sister knocked on the door. I was making breakfast for my daughter. She said, 'You need to sit down I've got some bad news.'

"I broke down and thought, 'It can't be true,' so I phoned my husband and he said it was true. I just cried and cried. That was the last time I spoke to him, I can't get through to him. We haven't heard anything from the kidnappers. All we can do is wait."

And, breaking down in tears, she recalled the last time she spoke with her son. She said: "I phoned him every day of the last two weeks. When I last spoke to him he said he couldn't wait to come home and have a jacket potato – he was fed up of the chapatis. He loves jacket potatoes with sweetcorn, cucumber, salad – he is a very healthy little boy.

"He is always smiling; he has lots of friends. He is very popular at school – he loves his friends and his teachers and his school dinners. He was having such a good time out there; he was excited about going there and seeing his grandmother."

The Foreign Office said it is providing consular assistance to the family. The British High Commission in Islamabad is also involved.