A man suspected of killing three people, including two children, after a dispute with his ex-wife's family is out of danger after an apparent suicide bid in north China.

The man surnamed Shi, 39, slashed his own head with a knife and attempted to jump off the fifth floor of a hospital building in Chengde City, Hebei Province, late Monday after police spent three hours trying to talk him down, said Liu Sheng, chief of Chengde's public security bureau, Tuesday.

Shi had undergone emergency treatment and was out of danger, said Liu.

Shi is alleged to have killed his ex-mother-in-law surnamed Chang and her two grandsons, aged 7 and 3.

Liu said that Shi, from Chengde's Zhangbaiwan Township, went Chang's rented home in Shaanxiying residential area at 5 p.m. Monday to "negotiate" remarriage to his ex-wife, but was refused.

He killed the three in the house, and locked the door before heading to Chengde Central Hospital, said Liu.

At the hospital he attacked and injured two women who were sisters of his ex-wife, said Liu.

Doctors said both women were seriously injured in the hospital.

A witness surnamed Chen said Shi repeatedly slashed at his own head, as police tried to persuade him to surrender.

Liu said that Shi divorced his wife surnamed Su in Febuary and tried to renew the marriage. Both Su and her family refused to consider Shi's proposal.