LONDON (AP) — The Latest on the second case of nerve agent poisoning in England (all times local):

11:35 a.m.

The Kremlin's spokesman says Russia is concerned with a second case of nerve agent poisoning in England, emphasizing that Russia has nothing to do with either case.

British police said Wednesday that a couple in their 40s were in critical condition after being poisoned by the same Soviet-designed agent that nearly killed former spy Sergei Skripal and his daughter Yulia in March. Britain blamed Russia for the March poisoning — an accusation Moscow vehemently denied.

President Vladimir Putin's spokesman Dmitry Peskov told reporters Thursday that "Russia has categorically denied and continues to categorically deny the possibility of any kind of involvement to what was happening there."

Peskov noted Britain has rejected Russia's offer for a joint probe, adding that "the British side has not presented any evidence of Russia's involvement in this, besides unfounded accusations."

11:30 a.m.

Russian lawmakers have speculated that a second case of poisoning by the nerve agent Novichok in England could be traced back to a British source.

British police said Wednesday that a couple got critically ill, poisoned by the same Soviet-designed agent that nearly killed former spy Sergei Skripal and his daughter Yulia in March. Britain blamed Russia for the Skripals' poisoning — an accusation Moscow fiercely denied.

Nikolai Kovalyov, a lawmaker and the ex-chief of Russia's FSB domestic security agency, told the Interfax news agency that the new poisoning may have been caused by "a psychologically unstable British researcher" who could have stolen the lethal toxin from a chemical lab. He didn't offer any evidence to back his allegations.

Another lawmaker, Alexei Pushkov, also pointed finger in Britain's direction, tweeting: "Something is rotten in the United Kingdom."

10:25 a.m.

British officials investigating a second case of poisoning with the nerve agent Novichok in southwestern England say they suspect the victims were not directly targeted but sickened as a consequence of the previous attack.

Police announced late Wednesday that specialists have determined that a couple in their 40s were poisoned by the same lethal toxin — developed by the Soviet Union — that almost killed Sergei Skripal and his daughter Yulia in March. The new victims are both critically ill in the same hospital that treated the Skripals.

"The working assumption would be that these are victims of either the consequence of the previous attack, or something else, but not that they were directly targeted," security minister Ben Wallace told the BBC.

07:45 a.m.

British officials are seeking clues in the rush to understand how two Britons were exposed to the military-grade nerve agent Novichok.

The country's chief counterterrorism police officer says specialists have determined that the couple in their 40s were poisoned by the same lethal toxin — developed by the Soviet Union — that almost killed a former Russian spy and his daughter in March.

It is not clear if the new victims were intentionally targeted.

The man and woman are critically ill in England's Salisbury District Hospital, where Sergei Skripal and his daughter Yulia were previously treated.

Home Secretary Sajid Javid is chairing a meeting of the British government's COBRA emergency committee on Thursday morning.