At least 21 people have been crushed to death in eastern Indonesia after a charity event by a wealthy family turned into a stampede, officials have said.

Police said 11 people were injured, several of them in critical condition, following the incident on Monday in the town of Pasuruan in East Java, some 800km east of the capital.

Harry Sitompul, the local police chief, said panic broke out among the crowd of several thousand who packed a narrow sidestreet waiting for a cash gift of Rp40,000 ($4.25) from the wealthy family.

Television footage showed women screaming as they were pushed into a fence by the crowd outside a house in Pasuruan.

Most of the dead were women, Budi, a worker at the morgue, said.

"They died because of a lack of oxygen or were trampled to death after being pushed from behind in the crush," he said.

Aminurahman, the town's mayor, said there were at least 2,500 people in the alley when the stampede began for unknown reasons.

"It's an annual activity from that family but there were a lot more people lining up today than in previous years," he told a local radio station.

"There was no co-ordination with police during the handout."

Cash handouts are commonly favoured by wealthy Indonesians during Ramadan, when most of Indonesia's 235 million people fast during daylight hours.

But crowd control is problematic and deaths have occurred at similar events in the past.