Wasila Tasi'u, 14, is on trial for allegedly murdering her husband, 35, with poison

A 14-year-old Nigerian child bride is facing the death penalty for allegedly murdering her 35-year-old husband with rat poison.

Prosecutors allege that Wasila Tasi'u, who comes from a poor, rural family in the north of the country, laced her husband Umar Sani's food with poison - perhaps because she regretted the marriage in April.

She is also accused of the murder of three other people, who are said to have died suddenly after eating the same meal prepared for a post-wedding celebration in the village of Unguwar Yansoro.

But the trial has angered activists who claim a girl who married a man more than 20 years her senior should be treated as a victim.

The case was opened yesterday with testimony from a seven-year-old child who says she was given money and sent to buy the poison on the same day Sani died.

Prosecutor Lamido Abba Soron-Dinki's first witness was a girl identified as Hamziyya, who was living in the same house as Tasi'u and her husband at the time.

Hamziyya was identified as the sister of Sani's 'co-wife', referring to a woman the deceased farmer had married previously in a region where polygamy is widespread.

She testified that Tasi'u gave her 80 naira ($0.45, 0.36 euros) to buy rat poison from a local shop on April 5.

'She said rats were disturbing her in her room,' Hamziyya told the court.

Wasila speaks with an unidentified defence counsel outside the courtroom during a break at her trial at Kano State High Court in the village of Gezawa

Wasila's parents stand outside the courtroom shortly after the first day of their daughter's trial

Father Tasiu Muhammad sits outside his house at Kaurar Naduni village, 62 kilometres outside the northern Nigerian city of Kano

Shopkeeper Abuwa Yusuf from the town of Unguwar Yansoro supported the story and confirmed selling the poison to the girl.

And neighbour Abdulrahim Ibrahim told the court that he was also offered the food allegedly prepared by Tasi'u - and saw Sani looking 'visibly ill' after eating.

He said: 'When he brought the food I noticed some sandy-like particles, black in colour.

He ate four of the small balls made of bean paste but 'was not comfortable with the taste', adding: 'It was only Umar (Sani) who continued eating.'

Sani Garba, 55, holds the picture of his 14-year-old daughter-in-law Wasila Tasi'u inside her abandoned matrimonial home in the village of Unguwar Yansoro, in northern Nigerian

Mr Garba, 55, stands in the abandoned bedroom of his 14-year-old daughter-in-law Wasila

He added that he took Sani home and learnt that three others who ate the food had died suddenly.

Prosecutors allege that Tasiu's poison food killed four people and have joined all the reported deaths into one murder charge.

Judge Mohammed Yahaya, sitting at the Gezawa High Court, has entered a plea of not guilty for Tasi'u, who refused to respond at a previous hearing on October 30 when the charges were put to her.

The judge has rejected defence applications for the case to be transferred to a juvenile court.

The last time Nigeria sentenced a juvenile to death was in 1997, according to Human Rights Watch.

The case continues.