The attacks came during a period when the Niger Delta Avengers are supposed to have agreed a truce with the government. Previously, the last attack they claimed was on June 16.
In a series of messages on Twitter early Sunday, the group said it had bombed two oil wells belonging to Chevron near the Abiteye flow station in the early hours of the morning as well as two pipelines owned by the Nigerian Petroleum Development Company close to the Batan flow station on Saturday.
The group also claimed to have targeted a Nigeria National Petroleum Corporation pipeline to the Warri refinery on Friday evening.
There was no official confirmation of the attacks.
Renewed violence in Delta state, where most of Nigeria’s oil comes from, has hit production with less than 1 million barrels per day produced in early June, down from 2.2 million in January, according to the government.
On June 13, the Avengers listed conditions necessary to begin dialogue with the government over ending their campaign, including a promise that oil firms should not extract oil or repair pipelines while the talks were ongoing.
Oil accounts for around 70 percent of Nigerian government revenues. The militants claim to be fighting to secure a greater share for the Delta communities that have suffered as a result of environmental damage.