An explosion at an outdoor celebration next to a Buddhist temple in northeastern Thailand killed seven people and wounded 27 others, police said Saturday. It was not immediately clear what caused the blast but police suspect that one of three men in a drunken brawl may have thrown a hand grenade. The explosion in Nong Bua Lamphu province, 420 kilometers (260 miles) northeast of Bangkok, occurred just before midnight on Saturday, when hundreds of people were in an open field celebrating the completion of a new temple pavilion with dancing and folk music, said Pol. Col. Thammajak Kongmongkol. Four women, one man, and two teenage girls near the stage where singers and dancers were performing were killed, he said. Six of the injured were in serious condition with shrapnel wounds, Associated Press reported.