Lagos , Nigeria ( CNN ) -- Two blasts shook a Nigerian government office Monday shortly after a rebel group sent out a message that it had planted bombs around the building , according to officials . No officials were hurt in the explosions in Warri in southern Nigeria , said Delta state government spokesman Linus Chima . It was not immediately known whether anyone else was wounded . The Movement for the Emancipation of the Niger Delta ( MEND ) claimed responsibility . It was the group 's first claim for an attack since calling off a cease-fire with the government in January . The bombs were mounted in vehicles located about 200 meters ( 656 feet ) away from the building , Delta state Commissioner for Information Oma Djebah said in a statement . Officials were meeting in the building to discuss steps forward with amnesty given to militants who agreed to lay down their arms . Present at the meeting were three state governors , including Delta state governor Emmanuel Uduaghan , and the minister for the Niger Delta . `` It was a plan to scuttle the peace talks , '' Chima said about the bombings . Participants in the conference were evacuated and the event `` has been put off , '' Djebah said without detailing when or if it would reconvene . `` The people of the Niger Delta will not be intimidated or deterred by the act of a few opposed to a peaceful and non-violent approach to resolving the historic grievances of the region , '' Djebah said . `` We assure all that we will not be deterred in our determination to fast-track our development for our people . '' In an e-mailed message , MEND had warned of three planted bombs , with the first to be detonated remotely at 11:30 a.m. ( 6:30 a.m . ET ) . Authorities have yet to comment on a possible third bomb . MEND , which has been battling the government for fairer distribution of the country 's oil wealth , threatened more violence . `` In the coming days , we will carry out a number of attacks against installations and oil companies across the Niger Delta and will spread out to companies such as Total which have been spared in the past , '' MEND spokesman Jomo Gbomo said in the statement . `` We hope the actions which will follow will persuade Mr. Uduaghan that we exist outside of cyberspace . '' The key militant group in the oil-rich Niger Delta is an umbrella organization of several rebel organizations . It initially called for a 60-day cease-fire in July and extended it in September , finally ordering a unilateral cease-fire on October 25 . Now-ailing President Umar Musa Yar'Adua offered amnesty to rebels who laid down their arms , and thousands -- including leaders -- did so . With the cease-fire , the government looked to broker peace and an end to the disruptions in its oil industry . Oil bandits have plagued Nigeria for years , attacking pipelines and cutting production by over one million barrels of oil a day . With an economy dominated by oil , Nigeria is the 16th biggest producer of crude oil in the world , according to the CIA 's World Factbook . In 2007 , fuel and mining products accounted for 97 percent of exports , according to the U.S. State Department . CNN 's Christian Purefoy contributed to this report .
Movement for the Emancipation of the Niger Delta ( MEND ) claimed responsibility . No officials were hurt in the explosions in Warri in southern Nigeria . - On March 26, a suicide bomber attacked an army checkpoint near Maiduguri, killing at least 10 soldiers and wounding 15 others. It was the group 's first claim for an attack since calling off a cease-fire .