The FTSE 100 sank on Tuesday morning on renewed fears of a Chinese slowdown hit commodity related companies.

Shares in Rio Tinto (LON:RIO), BHP Billiton (LON:BLT), Antofagasta (LON:ANTO) and Anglo American (LON:AAL) were all down over 5%, after sector wide downgrades by Credit Suisse.

Among the downgrades, Antofagasta had its price target slashed to 510p and Glencore’s lowered to 175p.

Iron ore fell 1.7% on the Dalian Exchange in China, adding to investor woes.

“It’s a continuation of the negative trend for basic resources companies as we have a high degree of uncertainty regarding emerging market economies. We have seen some negative earnings revisions for the sector in the past weeks,” Christian Stocker, equity strategist at UniCredit in Munich, said to Reuters.

“If China manufacturing numbers come in better than expected tomorrow, we could see a rebound in mining stocks for some days, but the sector’s medium-term outlook remains bearish.”

By mid-morning the FTSE 100 was down around 2% in London trading.