An Egyptian militant group claimed responsibility on Friday for an attack on a three-car police convoy that killed one policeman and wounded three others the day before.

The claim was made by Hasm group, a smaller militant faction that the government believes is a splinter of Egypt's now-outlawed Muslim Brotherhood. It routinely targets Egyptian security forces in bombings and drive-by shootings.

The Brotherhood, once the largest Islamist group in Egypt, has been the target of a heavy security campaign the past three years, since the military's ouster of the country's first freely elected president, Mohammed Morsi, who hails from the group.

"This is in response to the blatant crimes ... including liquidation of those in forced disappearances," the statement said. It was referring to series of killings of suspects who authorities said were killed in a shootout with security forces. Hasm claims that they were detained and then killed in custody.

Egypt's state-run news agency said gunmen on Thursday attacked policemen in Fayoum, an oasis province southwest of Cairo and a traditional stronghold of the Brotherhood.

Insurgents have carried out series of suicide bombings and attacks in Egypt since Morsi's ouster. The violence has been concentrated in the northern Sinai Peninsula, but it has also spread to the mainland, including the capital, Cairo.

The Fayoum attack came a day after the United States urged Americans to consider the risks of travel to Egypt.