Smoke billowing from a fire at a petrochemical plant operated by LyondellBasell in Berre-l'Etang, near Marseilles, in southern France yesterday, after two explosions earlier in the morning, a source in the investigation said. Police said no one was injured in the explosions. According to a source close to the government, criminal intent is suspected in the incident, which came as France celebrated its Bastille Day national holiday.