The Nigerian state security agency announced on Friday that it thwarted plans by militants to detonate explosives in four cities in the north of the country during celebrations to mark the Islamic Eid al-Fitre holiday.

The Department of State Services (DSS) said the attacks were planned in Kano, Sokoto, Kaduna and Maiduguri during the June 26and 27 public holidays to celebrate Eid, which marks the end of Islam’s holy month of Ramadan.

Maiduguri and surrounding parts of the northeastern Borno state have been attacked by suspected Boko Haram terrorists in the last few weeks including suicide bombings that killed 12 people on Monday and a raid on June 7 which killed 14.

The DSS said since Tuesday it had arrested three suspects – two in the northwestern city of Sokoto and another in Kano in the north – and seized weapons including eight assault rifles, 27 hand grenades and live ammunition.

“Their aim was to hit on soft targets such as markets, public parks, public processions, recreation centres, as well as worship centers especially the Eid praying grounds and other densely populated areas,” it said in a statement.

The DSS did not specify who it thought was behind the plans. Boko Haram has killed more than 20,000 people and forced some 2.7 million people to flee their homes in the last eight years in its attempt to create a state adhering to a strict interpretation of sharia law in northeast Nigeria.

In April, the DSS said it had thwarted Boko Haram plans to attack the British and United States embassies in the capital Abuja.