Sept. 17 (UPI) -- The Soviet-era nerve agent that poisoned Sergei Skripal and killed a woman this year is not what sickened two people at a British restaurant over the weekend, investigators said Monday.
Hazardous materials crews cordoned off the Prezzo restaurant and nearby streets in Salisbury late Sunday after a couple became ill there.
The conditions of the man and woman Monday were not reported.
Because the couple fell ill in Salisbury, authorities were concerned they might have come into contact with the same poison that fell Skripal, a former Russian spy, his adult daughter in March and another British couple in June. All four were sickened by novichok, a poison manufactured by Moscow during the Cold War.
"We can now confirm that there is nothing to suggest that novichok is the substance," Wildshire Police said in a statement. Monday. "At this stage it is not clear if a crime has been committed and inquiries remain ongoing."
Earlier this month, British authorities charged Ruslan Boshirov and Alexander Petrov in the poisonings but have not yet been able to arrest them.
The Skripals recovered after weeks in the hospital, but fallout from the attack has contributed to declining relations between the Kremlin and London and Western allies. Russian ambassadors have been kicked out of several countries and a European arrest warrant has been issued for Boshirov and Petrov, who are believed to be in Russia and protected by nonextradition laws.
Russian President Vladimir Putin said the men are civilians with no ties to Moscow or the GRU, a Russian intelligence agency.
Boshirov and Petrov appeared on Kremlin-funded television Sept. 13 saying they were innocent tourists visiting London.