At least 34 people have been killed by armed men after an attack on a cattle market in northeastern Nigeria, an emergency source says.

"Thirty-four bodies were deposited at the hospital," the official said, adding that the toll is likely to climb.

Emergency workers say the attackers used explosives in the attack on Wednesday night in the city of Potiskum.

The attack was believed to be in reprisal for an incident earlier in the day, when a gang sought to rob the market but was fought off by traders who caught one of the attackers, police said.

The man who was caught was doused in petrol and a tyre was placed around his neck before he was burnt to death, according to police and residents.

"A group of gunmen armed with around 20 explosives and assault rifles attacked the Potiskum cattle market," Toyin Gbadegesin, a police spokesman, said.

"They threw explosives and shot indiscriminately, setting fire to the market, killing lots of livestock and wounding many people, mostly cattle dealers."

Al Jazeera's Yvonne Ndege reporting from Abuja said: "Most of the individuals did manage to escape. The entire area has been cordoned off for the past twenty four hours, as the authorities try to investigate what had taken place."

Higher toll expected

Officials said the toll was likely to be more than 50 dead because families were also burying relatives' bodies without bringing them to the hospital.

Residents described a terrifying scene at the market usually crowded with traders, with scores of cattle burnt, the market razed and dozens of people killed.

One resident said firefighters were at the scene on Thursday morning searching water wells out of fears that residents had fallen in and drowned while trying to flee.

Residents crowded a local hospital to determine if their relatives were among the dead.

Gangs often seek to provoke panic at markets, forcing traders to flee so they can steal their wares.